ABSTRACT The study included two hundred and thirty samples of which 130 patients women of breast cancer in Iraqi population,, their ages ranged from 29 to 71 year (ages mean 42.95 ± 1.5) and 100 controls (healthy women), their ages ranged from 25 to 65 year (ages mean 31.37 ± 1.9). We confined the frequency of TNF-α gene -308G/A polymorphism by TARMS PCR technique (Tetra-amplification refractory mutation system-polymerase chain reaction technique). Also, we determined the association of TNF-α gene -308G/A polymorphism with breast cancer of Iraqi women population. Statistical results showed significant difference in genotype frequency of TNF-α gene -308G/A polymorphism with breast cancer women patients and control (healthy women). The A allele showed high frequency in breast cancer patients comparison with control (healthy women) and present with etiological fraction risk (EF) of breast cancer patients in Iraqi women, and its ratio 64.23% in patients while in control 50.50%. The G allele shows high frequency in control comparison with breast cancer patients was 35.77% and 49.50% respectively, and present related with protective fraction (PF) with breast cancer patients was (0,21.4). The genotypes of AA and GG (homozygotes) shows high frequency in breast cancer patients was 58.46% and 30% respectively, comparison with control was 16% and 15% respectively, also AA and GG homozygotes genotypes showed relationship with etiological fraction risk of breast cancer in women patients, while the GA heterozygote genotype show high frequency in control (healthy) was 69% comparison with breast cancer patients was 11.54%, and show related with preventive fraction of breast cancer patients. Our findings demonstrate that the TNFα -308G/A gene polymorphism may represent a risk factor for breast cancer development of patient’s women in Iraqi population.