Improper diet and physical inactivity are environmental risk factors for breast cancer (BC). This study evaluated the association of dietary risk factors and physical activities with different molecular subtypes of BC. We conducted a case-control study among 130 cases of BC and 150 age-matched controls. Demographic data and tissue marker status were obtained. Diet was assessed using Food Frequency Questionnaire and physical activity was determined using Physical Activity Questionnaire. The association between diet and physical activity with the cancer status was evaluated by Pearson's Correlation. Among the various dietary factors, refined oil displayed a weak albeit significant positive correlation (r = 0.344) to Luminal B subtype of BC. Consumption of all kinds of non-vegetarian food exhibited significant elevation in BC risk with OR > 1.9 (95% CI 0.825-2.707). A higher odds ratio (>1.66) was observed in individuals who had a limited intake of fruits. Furthermore, a strong association was found between low physical activity and breast cancer risk, with around 14.6% of cases being distinctly linked to this risk (OR = 3.33, 95% CI 1.158-9.403, p < 0.01). In essence, while dietary factors exhibited a negative correlation with breast cancer risk, the risk was heightened by physical inactivity.