Objective:To investigate the efficacy and safety of daratumumab-based regimens for the treatment of relapsed/refractory multiple myeloma (RRMM).Methods:A retrospective case series study was conducted. Thirty-seven RRMM patients treated with daratumumab-based regimens at Shanxi Bethune Hospital from January 2017 to November 2023 were selected, and their efficacy and adverse reactions were analyzed.Results:The median age [ M ( Q1, Q3)] of 37 RRMM patients was 62 (56, 68) years, the median number of previous treatment lines was 2 (1, 3.5) lines, 12 cases (32.4%) had extramedullary lesions, 12 cases (32.4%) had lactate dehydrogenase (LDH) ≥ 245 U/L, and 11 cases (29.7%) had previously received the third-line or more treatment. Among 27 patients who completed fluorescence in situ hybridization testing, 8 cases (29.6%) had high-risk cytogenetical changes. The median time from diagnosis to use of daratumumab was 23.1 (5.9, 52.0) months. The overall response rate (ORR) of 37 RRMM patients after treatment was 75.7% (28/37), with ORR of 88.0% (22/25) and 50.0% (6/12) for patients without and with extramedullary lesions, respectively, and the difference was statistically significant ( P = 0.036). The median follow-up time was 12.3 (4.6, 22.7) months, the median progression-free survival (PFS) time was 7.8 months (95% CI: 2.0- 13.7 months), and the median overall survival (OS) time was 22.4 months (95% CI: 17.5-29.5 months). The median PFS time for patients without and with extramedullary lesions was 11.8 and 4.2 months, and the median OS time was 23.5 and 8.3 months, respectively, and the differences in PFS and OS between the two were statistically significant (both P < 0.05); the median PFS time for patients with LDH ≥ 245 U/L and < 245 U/L was 6.5 and 11.9 months, and the median OS time was 30.2 and 12.1 months, respectively, and the differences in PFS and OS between the two were statistically significant (both P < 0.05). The incidence of non-hematological adverse reactions was 32.4% (12/37), with the most common being infusion-related adverse reactions (29.7%, 11/37), all of which were grade 1-2; the incidence of ≥ grade 3 hematological adverse reactions was 13.5% (5/37), with thrombocytopenia being the most common (8.1%, 3/37). Conclusions:The ORR of RRMM patients treated with daratumumab-based regimens is high, and the adverse reactions are tolerable.