Patients with systemic lupus erythematosus (SLE) are at increased risk for various plasma cell dyscrasias, but the coexistence of SLE and multiple myeloma (MM) are rarely reported to date. Due to the rarity, the clinical features of MM associated with SLE have not been elucidated, and the pathogenesis under this association remains unclear. In this report, we investigate a 31-year-old woman with 5-year history of SLE, who is diagnosed as IgA λ-type MM with multiple lymph node involvement. We discuss the clinical features of MM in SLE by reviewing previous cases and possible mechanisms connecting the two conditions.