Dermatologic manifestations are quite common in patients with adult T cell leukemia/lymphoma and myelopathy/tropical spastic paraparesis associated with infection with human T cell lymphotropic virus type-1 (HTLV- 1). In this study, we evaluated the dermatologic lesions of eligible blood donors in the state of Minas Gerais in Brazil who were seropositive but asymptomatic for infection with HTLV-1. The study population was composed of 128 HTLV-1-seropositive individuals and 108 seronegative controls. All individuals underwent a dermatologic evaluation. Biopsy specimens were obtained from abnormal and normal skin samples of seropositive individuals in an attempt to detect HTLV-1 in tissue samples by a polymerase chain reaction. Dermatologic alterations were observed more fre- quently in the seropositive group (adjusted odds ratio [OR] _ 8.77, 95% confidence interval [CI] _ 4.11−18.71). The most common skin diseases were dermatophytoses (adjusted OR _ 3.32, 95% CI _ 1.50−7.35), seborrheic dermatitis (OR _ 3.53, 95% CI _ 0.67−24.66), and acquired ichthyosis (P _ 0.001). Virus was detected more frequently in abnormal skin samples. Dermatologic lesions probably related to HTLV-1 infection were diagnosed in eligible blood donors who were infected with this virus, who were previously considered to be asymptomatic carriers of HTLV-1.