Clear cell sarcoma, also called malignant melanoma of soft parts, is an uncommon neoplasm that involves tendons or aponeuroses of the lower extremity. The CT features of a clear cell sarcoma arising from the abdominal wall with later peritoneal dissemination are described. Peritoneal sarcomatosis from soft tissue sarcomas is a very rare condition previously unreported in the radiologic literature. Metastases to peritoneal surfaces must therefore be considered a possible site for systemic dissemination of soft tissue sarcomas.