Malignant melanoma is an aggressive tumor with frequent metastasis. Although it often metastases to regional lymph nodes, it may also spread to organs such as lung, liver, central nervous system and bones. But synovial membrane metastasis like it is in our case is rare. 70 year-old male patient admitted to our hospital with a complaint of swelling in the right knee. In patient’s background, there was malignant melanoma history in right heel skin four years ago. MR imaging revealed solid lesion and fluid collection of 7 cm diameter in the right knee and fine needle aspiration was performed. Due to cytomorphological findings and HMB-45 and MelanA immunocytochemical positivity, patient was diagnosed as malignant melanoma metastasis. Although malignant melanoma often shows metastasis, synovial membrane metastasis is extremely rare.