Four cases of desmiod tumors of the anterior abdominal wall recently treated at the University of Chicago Hospitals and Clinics are presented. From our experience we conclude: 1. Inadequate excision of desmoid tumors results in local recurrence. 2. Adequate excision of desmoid tumors ot the abdominal wall sometimes necessitates creation of an abdominal wall defect too large for primary closure. 3. Marlex mesh has been used successfully in reconstruction of the abdominal wall following adequate excision of desmoid tumors. 4. One patient (Case 4) with an abdominal wall desmoid tumor associated with familial polypisis and mesenteric fibromatosis has benefited greatly following wide excision of abdominal wall and reconstriction using Marlex mesh, despite the fact that the mesenteric fibrous tumor was unresectable.