Background Elderly multiple myeloma (MM) patients are underrepresented in randomized clinical trials (RCTs). Prospective registries provide insight into real-world patient characteristics, treatment and outcome. The Danish Multiple Myeloma Registry (DMMR) and the Swedish Myeloma Registry (SMR), established in 2005 and 2008 respectively, are nationwide prospective registries with near 100% coverage. Methods We describe baseline characteristics, treatment and survival for patients diagnosed with active myeloma in the DMMR January 1st 2005-February 18th 2020, and the SMR January 1st 2008-December 31st 2019. We performed a retrospective comparison of patients aged ≥75 years at diagnosis to MM patients Results In total, we report on 4647 Swedish and Danish MM patients ≥75 years at diagnosis compared with MM patients 75 years, while the MAIA trial (Dara-Rd vs Rd) has the largest proportion of elderly patients among these studies (43.6%). However, in the MAIA trial only 29% of patients presented with ISS III, compared to 46% of patients ≥75 years in our real-world population. Similarly, 35% of patients in VISTA and 38% in ALCYONE had ISS III. The FIRST trial had a composition more similar to the Swedish and Danish registry population with 35% of patients >75 years, and 48% of these patients with ISS stage III. The treatment strategies in the elderly were similar in Denmark and Sweden. Melphalan and prednisolone (MP) were replaced by bortezomib-based regimes from around 2012, while lenalidomide-based treatment increased in recent years. Median relative survival (RS) for patients ≥75 years in Denmark increased from 25 months to 36 months for patients diagnosed 2005-2007 and 2015-2016, respectively. Similarly, in Sweden the median RS increased from 24 months to 42 months for patients ≥75 years diagnosed 2008-2009 and 2016-2017, respectively. Conclusion The real-world MM population is older and has a higher proportion of patients with ISS III disease than patients included in the pivotal RCTs, and compared to the younger patient cohort. Future studies in MM patients should take this into account.