This study was performed to study the effects of dietary factors on breast and cervical cancer incidence in female Koreans. The subjects were 60 breast and 109 cervical cancer patients recruited from five general hospitals in Seoul. Food intake, anthropometric measurement, and blood compositions were studied through personal interview and using medical records, from August 1991 to September 1992. Body weight, body mass index, triceps skinfold thickness and body muscle mass were at upper limit of normal value, which suggest that these patients had a tendency of overweight. The levels of hemoglobin and hematocrit of the patients were below the normal values. The values of serum protein, albumin, and calcium were in the normal range but close to the lower bound. Therefore the nutritional status assessed by blood composition seems to be marginal. The results of diet history showed that most of the nutrient intake of the subjects met with RDA. The fat intake were 22.9-36.9g/day which supplies about 15-16% of total calories. The results of this study do not agree with those reports of western societies which showed the positive correlation between calorie and fat intake and the incidence of breast and cervical cancer. Even through the calories and fat intake of the subjects were not high, it was higher than national average, especially in breast cancer patients. From this study, dietary factors does not seem to be a major risk factor in cancer incidence in Korea. However, the tendency of the increasing consumption of fat could be a contributing risk factor together with overweight.