Acromegaly is associated with an increased prevalence of colonic polyps. The aim of this study was to evaluate the prevalence and recurrence rate of colonic polyps in acromegalic patients. Ninety-six acromegalic patients and 100 irritable bowel syndrome patients (IBS) were enrolled in the study. Twenty patients who were cured exclusively by surgery, and 20 patients that could not be hormonally controlled were re-examined colonoscopically after 36 months. Twenty-nine of 96 acromegalic patients (30.2%) had colonic polyps. In the IBS group, 10 (10.0%) had colonic polyps. The prevalence of colonic polyps was significantly higher in acromegaly. The group of acromegalic patients with and without polyps did not differ significantly with regard to plasma GH, IGF-I, fasting insulin levels and glycemic status. The presence of colonic polyps was correlated with increased patient age and male gender. We did not observe a difference in terms of polyp recurrence frequencies in the patients cured by surgery compared to uncontrolled patients. Acromegalic patients have a higher prevalence of colonic polyps than that of control subjects. We could not identify any factors that could predict polyps within the acromegalic patients - but age and male sex.