The literature reflects a poor prognosis for women with endodermal sinus tumor. Two women with this neoplasm, 1 having stage IA and the other stage IIB disease were treated for 1 year postoperatively with a combination of actionmycin.D, 5-fluorouraciI, and cyclophosphamide. Each had therapy discontinued after a negative second laparotomy and 15 and 21 months later arc without recurrence. It is suggested that this drug regimen is a beneficial adjunct to surgery in the treatment of endodermal sinus tumor.