The aim of this study was to assess the effectiveness of sulindac therapy for eradication of micropolyps in 8 patients with familial polyposis coli. All patients had undergone colectomy and ileoproctostomy 4.5 years (range 3 months-20 years) before and had tubulous adenomas micropolyps in the rectum. Initial sulindac therapy 200 mg or 300 mg daily was started in all patients and was continued in 7 patients. In these 7 patients macroscopic and microscopic eradication of micropolyps was obtained within 3.4 months (1-8). After discontinuation of sulindac therapy, recurrence of micropolyps occurred in 4 patients within 3 to 4 months. Three patients had no recurrence with a follow-up of 1 to 19 months. A new eradication of micropolyps was obtained in these 4 patients with a second sulindac cure within 3 to 6 months. These observations confirm the effectiveness of sulindac therapy for eradication of tubulous adenomas micropolyps in familial polyposis, but after discontinuation of therapy, recurrence is frequent. Continuous or intermittent therapy might reduce recurrence.