Between 1971 and 1985, 598 patients with ovarian carcinoma were treated with abdomino-pelvic radiation therapy. Acute complications included nausea and vomiting in 364 patients (61%) which were severe in 36, and diarrhea in 407 patients (68%), severe in 35. Leukopenia (less than 2.0 x 10(9) cells/liter) and thrombocytopenia (less than 100 x 10(9) cells/liter) occurred in 64 patients (11%) each. Treatment interruptions occurred in 136 patients (23%), and 62 patients (10%) did not complete treatment. In both situations the most common cause was myelosuppression. Late complications included chronic diarrhea in 85 patients (14%), transient hepatic enzyme elevation in 224 (44%), and symptomatic basal pneumonitis in 23 (4%). Serious late bowel complications were infrequent: 25 patients (4.2%) developed bowel obstruction and 16 required operation. Multivariate analysis was unable to determine any significant prognostic factors for bowel obstruction; however, the moving-strip technique of radiation therapy was associated with a significantly greater risk of developing chronic diarrhea, pneumonitis, and hepatic enzyme elevation than was the open beam technique. We conclude that abdomino-pelvic radiation therapy as used in these patients is associated with modest acute complications and a low risk of serious late toxicity.