Adult T-cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell lymphoma caused by the human T-lymphotropic virus type-1 (HTLV-1). The skin is affected in approximately half of ATLL patients, and it may be the first manifestation of the disease. The skin lesions of ATLL are polymorphous, and depending on the type of skin eruption, it is possible to predict the prognosis of the disease. Besides specific skin lesions, other non-specific lesions and increased risk of cutaneous and systemic infections are observed. In this article, we describe the different skin lesions of ATLL patients (specific, non-specific, and infectious lesions), the different histopathological patterns, and the association of clinicopathological characteristics with prognosis. Recognition of ATLL skin lesions is essential for the correct management and the search for the virus, even in non-endemic regions, where global migration may bring HTLV-1 infected individuals.