This post-marketing surveillance assessed the safety and effectiveness of isatuximab plus pomalidomide and dexamethasone (Isa-Pd) for relapsed or refractory multiple myeloma (RRMM) during real-world use in Japan. Data from 211 individuals with RRMM treated with Isa-Pd in Japan between October 2020 and October 2021 were collected, with follow-up for up to 12 months after initiation of Isa-Pd or until treatment discontinuation. The incidence of adverse drug reactions (ADRs), ADRs of special interest (infusion reactions, bone marrow suppression, infections, cardiac disorders, other ADRs of Grade ≥ 3), and serious ADRs was assessed. Best overall response and overall response rate (ORR) were determined. In the safety analysis set (n = 120), ADR incidence was 57.5%. Most ADRs were hematologic, and serious ADRs occurred in 28.3%. Bone marrow suppression occurred in 46.7% of participants (19.2% serious), infusion reactions in 18.3% (6.7% serious), infections in 11.7% (8.3% serious), and a serious cardiac disorder in one participant; other Grade ≥ 3 ADRs were reported in 3.3% (1.7% serious). In the effectiveness analysis set (n = 108), the most common best overall response was very good partial response (24.1%), and ORR was 51.9%. These findings support the safety and effectiveness of Isa-Pd for RRMM in real-life settings in Japan.