Desmoplastic small round cell tumor (DSRCT) is a rare and highly malignant mesenchymal tumor found in the abdominal cavity. It mainly affects young male patients. We report a case of DSRCT that occurred in the abdominal cavity of a 50-year-old man. The tumor was characterized by small round tumor cells with irregular nests in the prominent desmoplastic stroma. The tumor cells showed immunoreactivity for epithelial membrane antigen, desmin, vimentin, and neuron specific enolase.