Melanoma is a cutaneous malignant neoplasm of melanocytes. Primary malignant melanoma (MM) of the lung is very rare. Although previous reports have described the radiologic features of pulmonary MM, its rarity makes the issues still unknown. Furthermore, there is little information regarding diagnostic application and/or usefulness of [18F]-fluorine-2-fluoro-2-de-oxy-D-glucose positron emission tomography (FDG-PET)-computed tomography (CT). Herein, we introduce a primary MM of the lung with multiple metastases, focusing on the radiologic imaging including PET-CT imaging. The pulmonary mass was presented as a round, well-demarcated, and multi-lobulated mass with an increased uptake of FDG on PET-CT images.