BACKGROUND Asymptomatic gallstones are commonly detected using preoperative imaging in patients with colorectal cancer (CRC), but its management remains a topic of debate. METHODS Clinicopathologic characteristics of patients who had asymptomatic gallstones presenting during the colorectal procedure were retrospectively reviewed. Medical records, including postoperative morbidity, mortality, and long-term gallstone-related diseases, were assessed. RESULTS Of 134 patients with CRC having asymptomatic gallstones, 89 underwent elective colorectal surgery only (observation group), and 45 underwent elective colorectal surgery with simultaneous cholecystectomy (cholecystectomy group). After propensity score matching (PSM), the complications were similar in the 2 groups. During the follow-up period, biliary complications were noted in 11 patients (12.4%) in the observation group within 2 years after the initial CRC surgery, but no case was found in the cholecystectomy group. After PSM, the incidence of long-term biliary complications remained significantly higher in the observation group than in the cholecystectomy group (26.5% vs 0.0%; P < .01). Multivariable logistic regression analysis identified female gender, old age (≥65 years old), and small multiple gallstones as independent risk factors for the development of long-term gallstone-related diseases in patients from the observation group. CONCLUSIONS Simultaneous prophylactic cholecystectomy during prepared, elective CRC surgery did not increase postoperative morbidity or mortality but decreased the risk of subsequent gallstone-related complications. Hence, simultaneous cholecystectomy might be a preferred therapeutic option for patients with CRC having asymptomatic gallstones in cases of elective surgery, especially for older patients (≥65 years old), female patients, and those with small multiple calculi.