Background: Population-based cancer registries are the best source of information to measure cancer burden. However, little is done to use this information for individual cancer risk assessment. In this study, we aimed at identifying women at high risk of breast and ovarian cancer using data on family history of cancer from the Israel national cancer registry. Methods: We used the family history assessment tool (FHAT) to score all females, 26 to 45 years of age, in a 2.6-million-member health provider in Israel (Maccabi Healthcare Services). Data on breast, ovarian, prostate, and pancreatic cancer history among the participants and their parents (identified using the national census) were retrieved from the national cancer registry. These data were used to calculate individual FHAT scores. Results: A total of 377,931 eligible women were included in the analysis. A relevant family history of cancer was detected in 20,386 (5.4%), with FHAT scores ranging from 1 to 16. FHAT score was higher in older women and among those with a history of breast cancer. Among women aged 35-39, an FHAT score of 10 or above was associated with an OR of 15.23 (95%CI: 7.41-28.19) for breast cancer compared to women with an FHAT of 0. Conclusions: Using individual-level data from national cancer registries may assist in detecting women with a relevant family history of cancer.