Objective: Maladaptive emotion regulation (ER) styles act as transdiagnostic mechanisms that underlie many psychiatric symptoms linked to cancer. ER and fear of compassion (FC) were studied in breast cancer, but their effects on psychiatric symptoms of colorectal cancer (CRC) patients are not studied. We aim to examine the role of ER and FC on depression and anxiety in Turkish CRC patients. Methods: This observational, cross-sectional study recruited 38 patients with CRC who were being followed up by the general surgery department of a university hospital. Emo tion Regulation Questionnaire, Fear of Compassion Scale, the Exercise of Self-care Agency Scale, Hospital Anxiety and Depression Scale, Distress Thermometer, Numeric Pain Intensi ty Scale, and Ostomy Adjustment Inventory were applied. Multiple regression analyses were performed to identify factors affecting depression and anxiety levels. Results: Twenty-nine men and 9 women (median age=56.5, 28–69), most of whom were married and highly educated, were recruited. Expressive suppression (p=0.013) and pain (p=0.010) positively (Model, R2 =0.42, p<0.001) and self-care agency (p=0.021) negatively influenced anxiety levels. Expressive suppression (p=0.017) and male gender (p=0.020) pos itively influenced depression levels (Model, R2 =0.28, p=0.003). There was no association be tween cognitive reappraisal and levels of depression and anxiety. Among ostomates (n=17), 11 patients had low and 6 patients had medium adaptation to an active ostomy. No patient exhibited high adjustment to an ostomy. Conclusion: Findings indicate that in CRC patients, expressive suppression affects levels of anxiety and depression while cognitive reappraisal does not. FC was not found to be related to anxiety and depression. Physicians should carefully observe the patients’ and the caregivers’ ER strategies and the dynamic and interactive psychological states to understand which patients need psychological and psychiatric interventions. We suggest future studies explore the interventions that target expressive suppression patterns to prevent anxiety and depression in CRC patients.