Abstract From December 1982 to December 1986, 52 patients with recurrent ovarian cancer were treated with single-agent HMM. Chemotherapy was given for a period of 1 year unless progression of disease or toxicity was noted. Survival was determined from the time of diagnosis to the date of death or September 30, 1992. The regimen was well tolerated with only one case of severe gastrointestinal toxicity. Nine patients were found to be clinically free of disease following completion of HMM treatment; they had initially responded to cisplatin-based therapy (i.e., potentially cisplatin-sensitive) and subsequently recurred. Four were found to have gross disease at the time of reassessment laparotomy. Three of these 9 patients are alive 81–92 months since diagnosis, having maintained disease-free intervals of up to 6 years. The median survival for the 9 patients without evidence of disease at the end of therapy was 75 months versus 9 months for the nonresponders. No patient who had progressive disease on first-line cisplatin-based combination chemotherapy (i.e., primary cisplatin-resistant) responded to second-line single-agent oral hexamethylmelamine. With a follow-up close to 10 years, our data show that hexamethylmelamine, with reasonable toxicity, can provide an extended, disease-free interval to a selected group of patients.