PurposeBreast cancer is the most common cancer in women worldwide and the leading cause of cancer death among women. In Asian countries such as Iran, the incidence of breast cancer is increasing. The present study aimed to assess the risk factors for breast cancer of women in Tabriz, Iran.MethodsA hospital-based case-control study was undertaken to identify breast cancer risk factors. The study consisted of 140 cases confirmed via histopathological analysis and 280 group-matched controls without any malignancy. Data were analyzed using descriptive and inferential statistical methods via the SPSS software version 18.ResultsIn a multivariate analysis, educational level (odds ratio [OR], 4.7; 95% confidence interval [CI], 2.11-10.83), menopausal status (OR, 2.54; 95% CI, 1.41-4.59), a high-fat diet (OR, 2.76; 95% CI, 1.51-5.04), abortion (OR, 2.13; 95% CI, 1.20-3.79), passive smoking (OR, 2.76; 95% CI, 1.51-5.04), oral contraceptive use (OR, 3.18; 95% CI, 1.80-5.59), stress (OR, 3.05; 95% CI, 1.74-5.36), and migration (OR, 3.09; 95% CI, 1.39-6.90) were factors associated with a significantly increased risk of breast cancer. Breastfeeding (OR, 0.39; 95% CI, 0.16-0.97) and a diet containing sufficient fruit and vegetables (OR, 0.22; 95% CI, 0.12-0.39) had protective roles against breast cancer.ConclusionThe study revealed that the risk factors for breast cancer among women in the Tabriz area of Iran are related to the lifestyle. Therefore, the provision of education to change unhealthy lifestyle choices and periodic check-ups for early breast cancer detection are recommended.