This study aimed to report the five-year clinical outcomes of anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR)-T cell (HDS269B) therapy in relapsed/refractory multiple myeloma (RRMM) patients, including those with poor performance status (Eastern Cooperative Oncology Group [ECOG] 3-4), and to identify factors influencing long-term outcomes. Forty-nine RRMM patients enrolled from 2016 to 2020 received HDS269B (9×106 cells/kg) after receiving a conditioning chemotherapy consisting of cyclophosphamide and fludarabine. The overall response, long-term outcomes, and safety were assessed, as were their associations with clinical and disease characteristics. With a median follow-up of 59.0 months, the overall response rate was 77.55%. The median progression-free survival (PFS) and overall survival (OS) were 9.5 months (95% confidence interval [CI], 5.01-13.99) and 20.0 months (95% CI, 11.26-28.74), respectively. The 5-year PFS and OS rates were 21.3% (95% CI, 12.3%-36.7%) and 34.1% (95% CI, 22.7%-51.3%), respectively. Patients with ECOG 0-2 had marked longer survival, with a median PFS of 11.0 months and median OS of 41.8 months. Early minimal residual disease negativity, and higher and persistent CAR-T cell expansion and absence of extramedullary disease were associated with better survival outcomes. No new CAR-T cell therapy associated toxicities were observed. Importantly, ECOG 0-2, prior therapy lines <4, and CAR-T cell persistence at ≥6 months were independently associated with longer OS. HDS269B is effective and safe, especially for patients with ECOG 0-2. Early CAR-T cell intervention may improve prognosis in patients with RRMM.