A case of extraskeletal osteogenic sarcoma arising in the soft tissues of the lower portion of the anterior abdominal wall (subumbelical region) is reported. The tumor developed in an area that had received telecobaltherapy 2 years 8 months previously (total skin dose of 9,000 rads delivered in 45 exposures over two separate periods of 106 and 141 days), after surgical treatment for a Stage I carcinoma of the uterine cervix. The clinical description and histopathology of this unusual neoplasm are presented, and the literature is reviewed.