We describe a case of a 34-year-old man who presented with a 10-year history of mycosis fungoides and recent onset of inguinal lymphadenopathy, fever, and cutaneous nodules on the right hip. Biopsy of the inguinal lymph node showed mixed cellularity Hodgkin's lymphoma. Biopsy of the pre-existing skin lesions showed mycosis fungoides, while that of the nodules on the hip revealed cutaneous Hodgkin's lymphoma. Immunohistochemical and molecular analysis demonstrated a null phenotype in the Reed-Sternberg cells of the Hodgkin's disease lesions, and a T-cell phenotype in the lymphoid cells of the mycosis fungoides lesions. He was treated with chemotherapy for Hodgkin's disease, which is in remission 11 years later. Topical nitrogen mustard and maintenance PUVA therapy have been used for the mycosis fungoides, which is also in remission.