Buschke-Ollendorff syndrome is an autosomal dominant disease characterized by disseminated connective tissue nevi of elastic type and osteopoikilosis. We report a 6-year-old Japanese boy with connective tissue nevi that showed slightly grouped yellowish or skin-colored papules and nodules, distributed from birth over his right thigh, right buttock, and back. Radiologic skeletal survey revealed osteopoikilosis. A skin biopsy specimen obtained from a papule showed that collagen bundles in the dermis were thickened and homogenized. The elastic fibers were not increased but were coarse and clumped. The boy's father, at age 34, has had osteopoikilosis and similar papules and nodules on his left buttock and back for the preceding 18 years. We studied the paternal grandfather, aged 65. He had osteopoikilosis and similar skin lesions on his lumbar region. None of the three had a history of hearing loss or malignant tumor. To our knowledge, this is the first report of three generations of Buschke-Ollendorf syndrome in a Japanese family.