Abstract： A case of primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma is reported. A 19-year-old male presented with multiple dark-erythematous plaques and small nodules over the body for 2 years. Histopathology of the skin showed a diffuse dense infiltration of small/medium-sized lymphoid cells around dermal vessels and appendages. The lymphoid cells had clear cytoplasm and twisted nuclei.Mitotic figures were observed. Immunohistochemistry showed positive staining for CD3, CD4, but negative staining for CD8, CD30 and CD20. The positive staining rate for Ki-67 was 25%. A diagnosis of primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma was made.