Despite the recently reported efficacy of daratumumab monotherapy for patients with relapsed or refractory multiple myeloma, outcomes in real practice following daratumumab monotherapy have yet to be investigated. A multi-center retrospective study of 16 Korean patients receiving daratumumab monotherapy for relapsed or refractory multiple myeloma was conducted. The overall response rate was 56.3%. Three patients with creatinine clearance <30 ml/min even achieved an overall response. The median progression-free survival was 2.7 months with 28.9% (95% CI, 9.0-52.8) of 6-month progression-free survival. All infusion-related reactions, including ≥Grade 3 back pain (6.3%) and dyspnea (6.3%), were manageable. The most common hematologic and non-hematological adverse events were anemia (62.5%) and upper respiratory infection (43.8%). ≥Grade 3 bacterial infectious adverse events were identified, including upper and lower respiratory infection (12.5% and 18.8%) and death following sepsis (6.3%). We observed acceptable outcomes of daratumumab monotherapy on relapsed or refractory multiple myeloma patients including even a few subjects with high comorbidity, despite relatively frequent infectious adverse events.