Objective: To report patient-reported outcomes of minimally invasive sacroiliac (SI) joint fusion as a case series., Methods: This study was a retrospective cohort study of patients 18 years of age and older who underwent a minimally invasive SI joint fusion by a single surgeon between 1 January 2013 and 31 December 2015. Routine demographic data, characteristics, and relevant surgical and clinical data were all collected for this group. In addition, patients completed preoperative and postoperative visual analog scale (VAS) and Short Form 36 (SF-36) questionnaires to assess outcomes. Patient selection for SI fusion was based on short-term resolution of symptoms (80% or greater relief) with an image-guided intra-articular injection of local anesthetic. Routine statistical analysis was performed using the Wilcoxon signed rank test, Fisher's exact test, or χ 2 analysis as appropriate., Results: This study included 19 patients comprising 24 SI fusions, with a mean follow-up of 58 months. The average patient age was 50 years and the average surgical blood loss was 25 cc. Men comprised 79% of the cohort. The VAS score improved from 7 to 3 (P = 0.0001). SF-36 physical function, role limitations due to physical health, and role limitations due to emotional health improved to a statistically significant extent. General health was not significantly changed. Every patient showed improvement in their SF-36 physical function scores (mean 40 preoperatively to 55 at final follow up) and 18 of 19 showed improvement in the VAS score (mean 7 preoperatively to 3 at final follow-up)., Conclusion: In appropriately selected patients, minimally invasive SI joint fusion results in decreased pain and improved physical functioning of patients, which is sustained for more than 4 years post-procedure., (© 2020 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)