OBJECTIVES The aim of this study was to evaluate the quality of life (QOL) of colorectal cancer patients seeking care at a tertiary referral center within the Social Security Mexican Institute (IMSS). METHODS Quality of life questionnaires were administered to colorectal cancer patients seeking care at the Hospital de Especialidades del Centro Medico Nacional de Occidente (CMNO) from July 2008 to February 2009. Evaluated patients under went informed consent, were 16 years of age or older, and had a colorectal cancer histological diagnosis (stage I,II, III and IV)). Patients were excluded if they had a second malignant neoplasm or incomplete information. To evaluate QOL, the validated Spanish version of the EORTC QLQ-C30 was administered to patients. This questionnaire evaluates global health status, five functional domains (physical, role, emotional, cognitive and social), three symptom scales (fatigue, nausea and vomiting, pain), and six single items (dyspnea, insomnia, appetite loss, constipation, diarrhea, financial difficulties) on a scale from 0 to 100 (0=death, 100=perfect health). The assessment calculates means and ranges for EORTC QLQ-C30 score items and statistical differences were estimated through ANOVA tests. RESULTS A total of 29 colorectal cancer patients were included in the analysis. The mean age of evaluated patients was 54 years±SD13, 55% were female, 72% were married, and 15% had completed elementary school. Patients presented various clinical stages of colorectal cancer, specifically I-1 (3%), II-9 (31%), III-9 (31%) IV-10 (34%). Global Health Status showed the following results: I:83.33, II:67.59, III:74.07, IV:67.50; p=0.87. On the other hand, patients with later stages of CRC reported greater fatigue (I-100, II-67, III-80, IV-47;p=0.08) and pain (I-83, II-50, III-67, IV-48; p=0.005). CONCLUSIONS Significant differences were observed in Mexican colorectal cancer patients symptoms in their clinical stages.