Background: Prostate-specific membrane antigen (PSMA)-PET was introduced into clinical practice in 2012 and has since transformed the staging of prostate cancer. Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) criteria were proposed to standardise PSMA-PET reporting. We aimed to compare the prognostic value of PSMA-PET by PROMISE (PPP) stage with established clinical nomograms in a large prostate cancer dataset with follow-up data for overall survival., Methods: In this multicentre retrospective study, we used data from patients of any age with histologically proven prostate cancer who underwent PSMA-PET at the University Hospitals in Essen, Münster, Freiburg, and Dresden, Germany, between Oct 30, 2014, and Dec 27, 2021. We linked a subset of patient hospital records with patient data, including mortality data, from the Cancer Registry North-Rhine Westphalia, Germany. Patients from Essen University Hospital were randomly assigned to the development or internal validation cohorts (2:1). Patients from Münster, Freiburg, and Dresden University Hospitals were included in an external validation cohort. Using the development cohort, we created quantitative and visual PPP nomograms based on Cox regression models, assessing potential PPP predictors for overall survival, with least absolute shrinkage and selection operator penalty for overall survival as the primary endpoint. Performance was measured using Harrell's C-index in the internal and external validation cohorts and compared with established clinical risk scores (International Staging Collaboration for Cancer of the Prostate [STARCAP], European Association of Urology [EAU], and National Comprehensive Cancer Network [NCCN] risk scores) and a previous nomogram defined by Gafita et al (hereafter referred to as GAFITA) using receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) estimates., Findings: We analysed 2414 male patients (1110 included in the development cohort, 502 in the internal cohort, and 802 in the external validation cohort), among whom 901 (37%) had died as of data cutoff (June 30, 2023; median follow-up of 52·9 months [IQR 33·9-79·0]). Predictors in the quantitative PPP nomogram were locoregional lymph node metastases (molecular imaging N2), distant metastases (extrapelvic nodal metastases, bone metastases [disseminated or diffuse marrow involvement], and organ metastases), tumour volume (in L), and tumour mean standardised uptake value. Predictors in the visual PPP nomogram were distant metastases (extrapelvic nodal metastases, bone metastases [disseminated or diffuse marrow involvement], and organ metastases) and total tumour lesion count. In the internal and external validation cohorts, C-indices were 0·80 (95% CI 0·77-0·84) and 0·77 (0·75-0·78) for the quantitative nomogram, respectively, and 0·78 (0·75-0·82) and 0·77 (0·75-0·78) for the visual nomogram, respectively. In the combined development and internal validation cohort, the quantitative PPP nomogram was superior to STARCAP risk score for patients at initial staging (n=139 with available staging data; AUC 0·73 vs 0·54; p=0·018), EAU risk score at biochemical recurrence (n=412; 0·69 vs 0·52; p<0·0001), and NCCN pan-stage risk score (n=1534; 0·81 vs 0·74; p<0·0001) for the prediction of overall survival, but was similar to GAFITA nomogram for metastatic hormone-sensitive prostate cancer (mHSPC; n=122; 0·76 vs 0·72; p=0·49) and metastatic castration-resistant prostate cancer (mCRPC; n=270; 0·67 vs 0·75; p=0·20). The visual PPP nomogram was superior to EAU at biochemical recurrence (n=414; 0·64 vs 0·52; p=0·0004) and NCCN across all stages (n=1544; 0·79 vs 0·73; p<0·0001), but similar to STARCAP for initial staging (n=140; 0·56 vs 0·53; p=0·74) and GAFITA for mHSPC (n=122; 0·74 vs 0·72; p=0·66) and mCRPC (n=270; 0·71 vs 0·75; p=0·23)., Interpretation: Our PPP nomograms accurately stratify high-risk and low-risk groups for overall survival in early and late stages of prostate cancer and yield equal or superior prediction accuracy compared with established clinical risk tools. Validation and improvement of the nomograms with long-term follow-up is ongoing (NCT06320223)., Funding: Cancer Registry North-Rhine Westphalia., Competing Interests: Declaration of interests MJK reports ownership of stocks in Bayer. JH reports participation on a data safety monitoring board for CARP-Study (carp-studie.de). VG reports grants or contracts from Pfizer, AstraZeneca, Bristol Myers Squibb (BMS), and MSD; consulting fees from BMS, Pfizer, Novartis, MSD Oncology, Ipsen, Janssen-Cilag, Eisai, Debiopharm, PCI Biotech, Gliead, Cureteq, Oncorena, and Synthekine; payment or honoraria from BMS, Pfizer, Ipsen, Eisai, MSD Oncology, Merck Serono, AstraZeneca, Janssen-Cilag, AAA/Novartis, Apogepha, Ono Pharmaceutical, Astellas Pharma, and Amgen; ownership of stocks in MSD, BMS, AstraZeneca, Genmab, and Bicycle Therapeutics; travel support from Pfizer, AstraZeneca, Janssen, Merck Serono, and Ipsen; participation on a data safety monitoring board or advisory board for the European Organisation for Research and Treatment of Cancer; and a leadership role for Arbeitsgemeinschaft Internistische Onkologie of the German Cancer Society. MS reports patents not related to the manuscript as planned, issued, or pending. ME reports grants or contracts from Blue Earth Diagnostics and Bayer; royalties from POSLUMA (an FDA-approved radiohybrid PSMA-targeted agent for PET imaging of prostate cancer in adults); consulting fees for Blue Earth Diagnostics, Novartis/AAA, Bayer, Telix, RayzeBio, Point Biopharma, and Janssen Pharmaceuticals; payment or honoraria from Novartis/AAA, Eckert-Ziegler, ABX, and Janssen Pharmaceuticals; patent application as inventor of radiohybrid PSMA; a leadership role in the European Association of Nuclear Medicine committee meeting; ownership of stocks in Novartis, Telix, Bayer, and Point Biopharma; support for travel from Blue Earth Diagnostics and Terumo; and payment for expert testimony from Paraxel and Bioclinica. TT reports grants from DAAD Researcher Grant and speaker fees from ABX. CK reports ownership of stocks in Telix and Actinium Pharmaceuticals; grants or contracts from Novartis, Mariana Oncology, and Amgen; payment or honoraria from Novartis and Pfizer; and travel support from Bayer, Janssen, and Amgen. KH reports grants or contracts from Novartis and Sofie Biosciences; consulting fees from Advanced Accelerator Applications, a Novartis company, Amgen, AstraZeneca, Bain Capital, Bayer, Boston Scientific, Convergent, Curium, Debiopharm, EcoR1, Fusion, GE Healthcare, Immedica, Isotopen Technologien München, Janssen, Merck, Molecular Partners, NVision, POINT Biopharma, Pfizer, Radiopharm Theranostics, Rhine Pharma, Siemens Healthineers, Sofie Biosciences, Telix, Theragnostics, and ymabs; payment or honoraria for educational events from PeerVoice; support for American Society of Clinical Oncology participation from Janssen; participation on a data safety monitoring board or advisory board for Fusion and GE Healthcare; and ownership of stocks in Sofie Biosciences, Pharma15, NVision, Convergent, Aktis Oncology, and AdvanCell. KR reports consulting fees from AAA/Novartis, Bayer, ABX, ABX-CRO, UroTrials, and Pharmtrace; honoraria or payment from AAA/Novartis, Bayer, and ABX; and travel support from Bayer. PTM reports payment to their institution from Siemens Healthineers. BAH reports consulting fees from Lightpoint medical, Janssen, Bayer, ABX, Astellas, Merck, Amgen, MSD/Pfizer, Novartis, BMS, Onkowissen, POINT Biopharma, Ipsen, AstraZeneca, Lightpoint medical, Telix, and Accord Healthcare; travel support from AstraZeneca, BMS, Janssen, Bayer, and Ipsen; grants or contracts from Janssen, Deutsche Forschungsgesellschaft, Novartis, and BMS; royalties or licenses from Uromed; payment or honoraria from Janssen, Amgen, Astellas, and Monrol; participation on a data safety monitoring board or advisory board for Janssen and ABX; and a leadership role for Deutsche Gesellschaft für Urologie. WPF reports grants from SOFIE Biosciences; consulting fees from Janssen, Calyx, Bayer, Novartis, and Urotrials; payment or Honoraria from Janssen, Calyx, Bayer, Novartis, Urotrials, Amgen, ABX, Eczacıbaşı Monrol, GE Healthcare, and Telix. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)