Skin diseases ranging from infective dermatitis to cutaneous lymphoma have been associated with human T cell leukemia virus (HTLV) type I. A generalized exfoliative papillated dermatopathy occurred in a rabbit 20 months into a course of chronic HTLV-I infection. Biopsies revealed epidermotropic T cell infiltrates, including Sezary-like cells, that resulted in a pattern mimicking cutaneous T cell lymphoma. HTLV-I was isolated from affected skin, and virus expression was detected in cutaneous cultures. Sezary-like cells also occurred in circulation. Interleukin-2-independent lymphocyte cultures, established from blood exhibiting elevated CD8 T cell levels and CD25 expression, had polyclonal integration of provirus. The findings are similar to those in evolving adult T cell leukemia lymphoma and may represent a prelymphomatous change. The cutaneous lymphoproliferative lesion resulted from HTLV-I infection and further establishes the New Zealand White rabbit inoculated with the RH/K34 cell line as a suitable model for investigation of HTLV-I pathogenesis.