A 57-year-old man was admitted with complaints of progressive anorexia, weight loss and right flank pain. He had been treated for basal-cell carcinoma of the skin 19 years before. On physical examination, eight moles in the face, back and left thigh were found along with palmar pits. In addition, a painful induration in his right thigh was evident. Biopsy proved that six moles were basal-cell carcinomas and the thigh mass a high-grade leiomyosarcoma. Computed tomographs revealed multiple metastases in the lungs and the liver. The patient was treated with epirubicin, with partial response, and subsequently with ifosfamide. He died 17 months after diagnosis. Whereas the world literature records several cases of soft tissue tumors in patients with nevoid basal-cell carcinoma syndrome, this is the first report of a simultaneous occurrence of leiomyosarcoma and nevoid basal-cell carcinoma syndrome.