Reiters syndrome is an unusual disease characterized a triad of nongonococcal urethritis, conjunctivitis, and arthritis in association with the mircoutaneous lesions of keratoderma blenorrhagica and balarintis circinata. We present herein a case of Reiters syndome combined yiti lung cancer. A 39-year-old man has experienced naigrating polyarthralgia and high fever ilitermittently for about 20 years, Hyperkeratotic erythemnous patches and plaques, which dyeliped about 1 year ago, have aggravated and expanded to the whole body. Histopathologic sections from the plaque on the right forc ari showed characteristic findings including thickened parakeratotic horny layer and spongiform micropustules of Kogoji He was associated with HLA-B27. On the chest X-ray, a thumbtip size mass was incidently found. Chest CT and bone scan findings supported lung cancer and multiele metastases. (Kor J Dermatol 1995;33(3): 580-584)