The optimal melphalan dose prior to autologous stem cell transplantation (ASCT) is not known for elderly multiple myeloma (MM) patients. We analyzed data of all MM patients ≥65 years (n = 388) enrolled in the observational Swiss Blood Stem Cell Transplantation Registry. The median age was 67 years (65-77). Single ASCT was performed in 344 (88.7%) patients, with 259 patients (75.3%) receiving a melphalan dose of 200 mg/m ² (MEL200), and 85 patients (24.7%) receiving lower doses (MELlow) (median 140 mg/m ² , range 70-180 mg/m ² ). MEL200 patients were slightly younger, and had a better renal function, but did not differ with regards to ISS stage, cytogenetic risk, remission status, and KPS. Overall mortality at day 100 was 1.5% without differences between the MEL groups (p = 0.621). Median progression-free survival (PFS) in the MEL200 and the MELlow group was 27.7 and 22.1 months, respectively (p = 0.294). Median overall survival (OS) in the MEL200 and in MELlow group was 91.2 and 61.2 months (p = 0.015). However, multivariate analysis showed no significant association of the melphalan dose and OS (HR 0.734; CI95% 0.264-2.038; p = 0.553). In conclusion, our data reveal no significant differences in safety and PFS for elderly myeloma patients treated with MEL200 or with lower MEL doses.