The data of the polyp registry of the Côte d'Or was used to study the characteristics of hyperplasic polyps detected in a well defined-population. In the 1976-1985 10-yr period, 1,222 hyperplasic polyps were resected in 874 Côte d'Or residents. They represented 17% of all polyps. The incidence rate standardized according to the world reference population was 21.9/100,000 in males and 8.1/100,000 in female. The male predominance was observed in all age groups. The incidence of hyperplasic polyps increased by a mean of 19.8% per year in males and 26.6% in females (P less than 0.001). Hyperplasic polyps were discovered twice as often in patients living in an urban area than in patients living in a rural area (P less than 0.001). Hyperplasic polyps were smaller than 5 mm in 91.4% of cases and were located in the rectum in 59.4% of the cases. They were associated with an adenoma in 21.0% of the cases. In the case of a rectal hyperplasic polyp, 10.5% of the patients had an adenoma in the left colon and 2.8% in the right colon. A rectal hyperplasic polyp cannot be considered as a marker of the presence of a large bowel adenoma. The relationship between hyperplasic polyp and colorectal cancer needs to be established.