Twenty-eight patients with advanced or recurrent adenocarcinoma of the endometrium were treated with m-AMSA. Twenty-four patients (86%) were treated at 30 mg/M2/d X 3d q 21 d and four patients were treated at 40 mg/M2/d X 3d q 21 d intravenously. Eighty-eight courses of m-AMSA were administered with a median of 2 courses per patient. One (5%) complete response occurred in 19 patients evaluable for response. Toxicity was well tolerated and generally mild. m-AMSA may be relatively inactive in the treatment of advanced adenocarcinoma of the endometrium; further studies, however, are required to determine its effectiveness in primary previously untreated disease.