Granuloma annulare is characterized by noncaseating dermal granulomas with connective tissue changes. A relationship with hematologic and solid malignancies has been suggested in some cases. We describe a 70-year-old man who had erythematous annular plaques on his elbows, upper extremities, and wrists for a period of 3 months. Histologic examination revealed epithelioid cell granulomas associated with dense atypical lymphocytes in the dermis. Immunohistochemical staining of skin specimens showed a prominent infiltration of CD3⁺, CD4⁺, CD5⁺, and CD25⁺ cells. Human T-cell leukemia virus type I proviral DNA was detected in the blood and cerebrospinal fluid by Southern blot analysis and polymerase chain reaction assay. The patient was given the diagnosis of adult T-cell leukemia/lymphoma based on the initial cutaneous manifestations. His condition progressed rapidly and led to his death. The granuloma annulare–like skin lesions in our patient could be considered as a peculiar immunologic hypersensitivity reaction of the host against the tumor cells or persistent human T-cell leukemia virus type I viral antigens. Dermatologists should be aware that this skin condition may be an initial manifestation of adult T-cell leukemia/lymphoma.