Patients with ovarian carcinoma refractory to chemotherapy received a sequential combination of ethinyl estradiol and medroxyprogesterone acetate in two dose regimens. There was no difference in therapeutic activity of the two dose regimens. Of 65 patients, nine (14%) responded to treatment and 13 (20%) had stable disease. Vascular complications occurred in three patients; hemiplegia developed in one of those. Nine patients had significant nausea and vomiting, and one experienced severe depression that required treatment withdrawal. The sequential and combined use of ethinyl estradiol and medroxyprogesterone acetate may provide an alternative treatment for certain patients with ovarian carcinoma that does not respond to optimum chemotherapy. Additional studies are required to determine if synergism exists between this treatment and other modalities of therapy. Further investigation is required into the vascular disorders that complicate therapy to determine whether appropriate preventive measures are possible.