O- methylation mediated by COMT enzyme is an important mechanism for inactivating Catechole Estrone (CE) which including 2- HE and 4- HE and transform it to 2-ME and 4-ME which act as anti- tumor genesis. This study aimed to investigate the association between the polymorphism in COMT genotype and the breast cancer risk in (40) young patient's women aged between (20-39) years were diagnosed and confirmed with breast carcinoma at AL- Sadder hospital in Missan, and (40) healthy control women aged between (18-39) years in the period between     September -2009 to April -2010 Odds ratios(OR) and confidence interval (CI) were calculated in level significant   P < 0.05. The statistical analysis showed no association between the breast cancer risk in young women and homozygous wild (Met/Met) genotype with an OR of 0.63(95%CI= 0.248 - 0.552 ), also with heterozygous  (Val/Met) genotype with an OR of 0.93 (95%CI= 0.155 - 0.44  ), and when a combination (Met/Met + Met/Val) genotype with an OR of 0.78 (95%CI= 0.559-0.841), compared to homozygous mutant  (Val/Val) genotype. No significant differences in frequency of low activity alleles between cases and controls, indicating the polymorphism as a single factor may not contribute to breast carcinogenesis in young women.