A 62-year-old woman diagnosed with asymptomatic IgG multiple myeloma in 1998 received distal gastrectomy because of abdominal fullness and was diagnosed with AL amyloidosis in 2009. She was referred to our hospital and further examination revealed amyloid depositions on the tongue, submandibular glands, heart, and gastrointestinal tract. Combination therapy of melphalan with dexamethasone was ineffective. She then received 13 courses of lenalidomide at 15 mg daily with weekly dexamethasone, which resulted in complete response with no detectable M-protein by immunofixation electrophoresis. Reduced-dose lenalidomide with dexamethasone is effective for patients with multiple myeloma complicated with AL amyloidosis.