A case-control study of 68 pathologically confirmed breast cancer patients and a normal control group was performed to evaluate xeromammographic parenchymal patterns and their relationship to breast cancer. The age distribution of the breast cancer patients was between 30 and 69 years with a mean age of 45. The younger age group below 50 was more frequent than the older age group over 50.Incancer patients compared with the normal control group, the prominent ductal pattern(P2) and the dense dysplastic pattern(DY) were 2.2 times more frequent than the no ducts visible pattern(N1) and the minor ductal pattern(P1). The older age group showed no statistically significant difference in distribution of cases according to the mammographic parenchymal patterns between breast cancer patients and the normal control group, but in the younger age group, the P2 adn DY patterns were associated with a relatively high risk more than the N1 and P1 patterns. So, women below the age of 50 who have a P2 or DY mammographic parenchymal pattern, even in the absense of symptoms, probably comprise a high-risk group and should also be followed up closely.