Bexarotene is a third-generation retinoid X receptor-selective retinoid that is widely used for the early treatment of advanced-stage cutaneous T-cell lymphomas. In this report, we describe a case of successful treatment of advanced primary cutaneous peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) with oral bexarotene monotherapy. After the administration of oral bexarotene at a dose of 300 mg/m2/day, all skin lesions and lymph nodes regressed, and complete remission was achieved for 1 year. Our case suggested that bexarotene monotherapy could be one of the possible therapies for the treatment of primary cutaneous PTCL-NOS.