This study presents the comparative pattern of risks for cancers of the breast, uterine cervix and ovary in relation to various risk factors based on the data from a case-control study conducted at the Korea Cancer Center Hospital in Seoul between August in 1996 and March in 1997. Included in the analysis were 128 women of breast cancer, 169 women of uterine cevical cancer and 45 of ovarian cancer confirmed by the historical diagnosis. Person interviews were conducted in all cases through standard questionnaire. Data were analyzed using multiple logistic regression, adjusting for potential confounding factors. In cancers of the uterine cervix and ovary, increasing risks were seen in earlier age at first menarch. Statistically significant associations were found with postmenopausal women in cancers of the breast(OR=2.0) and ovary(OR=8.5). The OR increased with late age at postmenopause in postmenopausal women of uterine cervical cancer(OR=7.0). Increasing number of pregnant and livebirths was associated with a higher risk of uterine cervical cancer(OR=2.7, 2.9). The risk of uterine cervical cancer was decreasing with increasing age at first birth(OR=0.2). Among postmenopausal women, the OR increased with BMI in breast cancer. A positive history of breastfeeding was associated with significantly lower risk of breast cancer(OR=0.4). There were no associations with anthropometric measurements(height, weight, BMI), smoking, alcohol intake, menstrual regularity, age at first marriage, number of marriage and induced abortion, and oral contraceptives in cancers of the breast, uterine cervix and ovary. In cancers of the breast and uterine cervix, decreasing risks were seen in intake of fresh fruits, carrot and cabbage.