A population based case-control study of epithelial ovarian carcinoma is proposed involving approximately 373 newly diagnosed patients and 1,200 controls in the San Francisco Bay Area. Data from structured personal interviews with 123 Caucasian patients and twice their number of age-matched hospital controls have already been keypunched and coded on tape. Funds are requested to interview an additional 240 patients and 960 controls in Santa Clara County. Controls will be matched to the patients on age and race. Two of the controls will be patients in the same hospital as the case; the remaining two controls will be selected from the Santa Clara County population by random digit dialing. The information requested from subjects will permit testing of hypotheses relating epithelial ovarian cancer risk to i) involuntary infertility, ii) oral contraceptive use, iii) timing and number of pregnancies and live births, iv) postmenopausal estrogen use, v) exposures to talc and other fibers, and other factors. Attention will be paid to adjusting for confounding and investigation of interaction among the above potential risk factors.