Lower starting doses of lenalidomide (LEN) are recommended for patients with renal impairment (RI). In the present study, we conducted a subgroup analysis of the MM-021 registration trial to investigate the efficacy and safety of LEN plus low-dose dexamethasone (LoDEX) in Chinese patients with advanced relapsed or refractory multiple myeloma (RRMM) based on levels of RI. Patients received LEN+LoDEX until disease progression or discontinuation. Patients were divided according to RI: no/mild [creatinine clearance (CrCl) ≥60 mL/min, n = 131], moderate (CrCl ≥30 to <60 mL/min, n = 54), and severe (CrCl <30 mL/min, n = 14). LEN starting dose was 25 mg/day on days 1-21, adjusted for baseline renal function. Best overall response rate was 48 %; in patients with no/mild, moderate, or severe RI, response rates were 50, 42, and 42 %, respectively. Median progression-free survival and overall survival were longer in patients with no/mild RI (9.3 and 22.4 months, respectively) versus those with moderate (6.9 and 16.0 months) or severe RI (4.8 and 11.1 months). LEN+LoDEX was well tolerated, although incidences of grade 3-4 neutropenia, anemia, and thrombocytopenia were higher in patients with severe RI. In Chinese patients with advanced RRMM and RI, adjusting the starting dose of LEN according to renal function did not compromise the efficacy or safety of LEN+LoDEX.