Limited evidence exists on the combined effect of lifestyle factors on breast cancer (BC) risk, particularly in developing countries. This study aimed to investigate the association between adherence to WCRF/AICR cancer prevention recommendations and BC risk among Moroccan women. We conducted a large case control study including 1400 cases and 1400 matched controls (by age and place of residence), between 2019 and 2023. A structured general questionnaire and a food frequency questionnaire were used for data collection. Adherence to cancer recommendations was assessed using a scale ranging from 0 to 7, including 7 components about: food categories, physical activity, healthy weight, and breastfeeding. Multivariate logistic regression models were used to calculate multivariable odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for Potential confounding variables. For each one-point increase in the WCRF/AICR adherence score, the odds of BC decreased by 67% overall (95% CI: 0.29–0.37). This inverse association was consistent among both premenopausal women (OR = 0.29; 95% CI: 0.24–0.35) and postmenopausal women (OR = 0.35; 95% CI: 0.30–0.41). Analysis of individual recommendations showed that being physically active, maintaining a healthy weight, breastfeeding, consuming a plant-rich diet, and limiting the intake of fast foods and other processed foods were the main key drivers of the observed inverse associations with BC. In conclusion, the present study suggests that greater adherence to the WCRF/AICR recommendations is associated with decreased risk of BC risk in Morocco. Prevention strategies should consider comprehensive interventions targeting multiple lifestyle factors.