The aim of this study was to estimate the prevalence of intestinal constipation and associated factors in adults 20 years and older. A cross-sectional study was conducted in the rural area of Pelotas, Rio Grande do Sul State, Brazil, in 2007. Intestinal constipation was defined according to the Rome III criteria. The study began with a descriptive analysis, followed by bivariate and multivariate analyses using Poisson regression. Prevalence of intestinal constipation was 26.9% (95%CI: 25.1-28.8). Women had 2.5 times more constipation than men (36.8% vs. 13.9%). The adjusted analysis showed that risk factors for men were age (>60 years), skin color (black/brown), and low economic status. Among women, age was inversely related, i.e., having a protective effect among the elderly. Intestinal constipation is common in this population. Associated factors were the same for men and women, except socioeconomic status, which showed no association in women.