Background Colorectal cancer is a growing public health concern in low- and middle-income countries, particularly in the context of nutritional transition and changing lifestyles. In Mauritania, evidence on factors associated with colorectal cancer remains limited. This study sought to identify nutritional, behavioral and anthropometric factors associated with colorectal cancer among adults living in Nouakchott. Methods A case-control study was conducted in Nouakchott between January and April 2026. The study included 50 confirmed colorectal cancer cases and 100 controls with no personal history of cancer. Data were collected using a standardized questionnaire covering sociodemographic characteristics, dietary habits, behavioral factors and anthropometric measurements. Crude and adjusted odds ratios with 95% confidence intervals were calculated using binary logistic regression. Results Low educational level was more frequent among cases than controls, 70.0% versus 27.0%, and remained independently associated with case status after adjustment (aOR = 4.98; 95% CI: 1.81-13.70; p = 0.002). Being married or living with a partner was also associated with case status (aOR = 3.72; 95% CI: 1.19-11.66; p = 0.024). Abdominal obesity was associated with colorectal cancer in bivariate analysis but not after adjustment. High consumption of salty foods remained associated with case status in the multivariate model (aOR = 47.45; 95% CI: 4.83-466.40; p = 0.001). However, this estimate should be interpreted with caution given the wide confidence interval and the limited sample size (n=50 cases). Refined sugars and canned foods were associated with case status only in bivariate analysis. Inverse associations observed for coffee and sugar-sweetened beverages should be interpreted cautiously because of possible reverse causality. Conclusion Low educational level and high consumption of salty foods were the most defensible factors associated with colorectal cancer in this study. These findings support strengthening nutrition-related prevention and health education interventions in Nouakchott. Larger studies with more detailed dietary assessment are needed to confirm these associations.