The relationship between prior cholecystectomy and colon cancer in women has been a subject of recent research interest. No study has yet reported on cholecystectomy and adenomatous polyps, a precursor lesion for most colon cancers. This pilot case-control study interviewed 245 women who had undergone colonoscopy between 1983 and 1985 at Columbia-Presbyterian Medical Center with a structured telephone-administered questionnaire. Fifty-six were colon cancer cases, 105 were adenomatous polyp (AP) cases, and 84 were controls (without colonic neoplasia). Adjusted for age and educational attainment, the odds ratio for prior cholecystectomy among colon cancer cases compared to controls was 1.79 (95% confidence limits, 0.59 to 5.44) and 2.26 for right-sided colon cancer cases (95% confidence limits, 0.61 to 8.42). Despite a lack of statistical power, these estimates are consistent with earlier reports. The odds ratio for adenomatous polyp cases was 1.02 (95% confidence limits, 0.40 to 2.64), suggesting no association between prior cholecystectomy and adenomatous polyps. These preliminary findings are currently being explored in a large-scale case-control study.