To the Editor.— Of 9,354 men examined in a prospective study, we were able to identify 270 who had a cholecystectomy a year or longer before examination, as confirmed by a subsequent hospital record review. The 270 men with cholecystectomy had a significantly lower age-adjusted mean serum cholesterol level of 208.2 mg/dL, compared with 216.4 mg/dL for the rest of the study population ( P This observation is relevant in view of two recent findings: first, cholecystectomy subjects had an increased risk for right-sided colon cancer 1,2 ; second, we found in a prospective study that a low serum cholesterol level in men increased their risk for colon cancer, especially on the right side, excluding the hepatic flexure. 3 Consequently, there is a suggestion that a low serum cholesterol level in cholecystectomy subjects may be related to an increased risk for right-sided colon cancer. A subsample of the examined menalso