The aim of the study is to analyze the relationship between personality traits of women with hereditary predisposition to breast/ovarian cancer and their obstetric history and cancer-preventive behaviors. A total of 357 women, participants of 'The National Program for Families With Genetic/Familial High Risk for Cancer', were included in the study. The Neo Five-Factor Inventory (NEO-FFI) and a standardized original questionnaire designed for the purpose of the study were used. Breast ultrasound examination at a younger age was associated with Extraversion. Openness to Experience was linked with lower number of children, more frequent use of hormonal contraceptives, and younger age at first breast ultrasound examination. Women with higher Agreeableness scores were less likely to use contraceptives and underwent their first breast ultrasound later in life. Conscientiousness was associated with more frequent use of hormonal contraceptives and younger age at first breast ultrasound examination. Women at increased risk for developing breast/ovarian cancer who used hormonal contraceptives underwent breast ultrasound examinations earlier in life, while those who had breastfed their children chose to have their first mammogram earlier in life. Personality traits affect health-related behaviors and should be taken into account when designing theoretical models as well as interventions regarding health habits.