['Colorectal cancer is the second leading cause of cancer-specific death in the USA. Evidence suggests people with mental illness are less likely to receive preventive health services, including cancer screening. We hypothesized that mental illness is a risk factor for non-adherence to colorectal cancer-screening guidelines.', 'We analyzed results of the 2007 California Health Interview Survey to test whether mental illness is a risk factor for non-adherence to colorectal cancer-screening recommendations among individuals age 50 or older (N\xa0=\xa015,535). This cross-sectional dataset is representative of California. Screening was defined as either fecal occult blood testing during the preceding year, sigmoidoscopy, or colonoscopy during the preceding 5\xa0years. Mental illness was identified using the Kessler K6 screening tool. Associations were evaluated using weighted multivariate logistic regressions.', 'Mental illness was not associated with colorectal cancer-screening adherence (OR 0.89; 95% CI 0.63-1.25). Risk factors for non-adherence included being female (OR 1.25; 95% CI 1.09-1.44), delaying accessing health care during the previous year (OR 1.89; 95% CI 1.56-2.29).'] Is mental Illness Associated with Adherence to Colorectal Cancer Screening : Results from the California Health Interview Survey?