Systemic lupus erythematosus is an autoimmune disease associated with mild valvular regurgitation. However, there have been no detailed reports of infective endocarditis in patients with systemic lupus erythematosus. Here, we describe a case of a 55-year-old woman without any cardiac abnormalities who was diagnosed with lupus nephritis by renal biopsy; she contracted infective endocarditis while receiving immunosuppressive therapy. Our case emphasizes that special consideration of the occurrence of infective endocarditis, and its early diagnosis and treatment are mandatory for patient survival. We propose that echocardiography should be performed before treating patients with systemic lupus erythematosus who have an uncertain cardiac status.