Nongenetic breast cancer risk factors have never been evaluated in Kuwait. Accordingly, we aimed at examining these factors as well as the immune profile of the patients. Fifty stage I breast cancer patients and 50 age group-matched normal controls were assessed for the level of their peripheral blood lymphocyte subsets and for risk factors associated with their demographic and reproductive characteristics and with diet. The percentages of CD4+ T lymphocytes, CD4+:CD8+ ratio, and CD19+ B lymphocytes were significantly higher in the patients as compared to controls, while the percentages of CD8+ T lymphocytes and natural killer (CD56+) cells were significantly reduced. Risk factors associated with the disease included higher BMI, lack of regular exercise and physical activity in the past 5 years, early age at menarche, late age at first pregnancy, lack of previous information about breast cancer, hormonal therapy, and presence in Kuwait during the invasion/liberation. Other parameters included significantly more frequent consumption of carbohydrate, sweets, animal fat, and vegetable oil (margarine) and less frequent consumption of fresh vegetables and olive oil. This is the first study to highlight the environmental risk factors associated with breast cancer among the Kuwaiti women. We recommend introducing a nationwide campaign to further investigate these factors and to address them accordingly.