Abstract Background: Approximately 10% of all cancers are caused by a strong genetic predisposition. Identifying those individuals at genetic risk for cancer is important for proper care for prevention. Guidelines exist for appropriate referral of individuals to Cancer Genetic Services (CGS), based on family and personal medical history criteria. However, only a minority of individuals at risk for cancer predisposition are recognized either by the patients' health care providers or the patients themselves. This may be due to a suboptimal family and personal medical history taken by their health care providers. Purpose: To evaluate whether the routine use of a screening questionnaire about personal and family medical history improves the detection of individuals that may be at risk of hereditary cancer of the breasts, ovaries and/or uterus. Methods: This pilot study was performed at the gynaecology outpatient clinic. The usual care (or common practice) referral rate to CGS, based on unstandardized anamnesis of family and personal medical history, was determined retrospectively between May 1, 2009 and April 30, 2010. Prospectively, the health care providers were asked to complete a questionnaire based hereditary cancer-risk screening tool for each new patient between June 1, 2011, and July 15, 2011. This screening tool was based on national and international guidelines, and provided a first global risk assessment of cancer predisposition. Individuals estimated to have an increased risk, were scheduled for a telephone consultation, in which a more detailed family and personal medical history was obtained to assess hereditary risk, and indication for CGS referral. Differences in proportions between groups were tested by the chi-square test. Results: In the usual care arm, 8 of the 8630 patients (0,09%) who attended the gynaecology outpatient clinic had been referred to CGS. In the prospective arm, 500 screening questionnaires were handed out of which 203 (41%) were completed by the same health care providers. Results showed that fourteen of the patients (6.9%) who fulfilled criteria for referral, already had previous genetic counselling. Twenty-four additional telephone consultations (11.8%) were conducted, from which in five patients (2.5%) CGS referral was indicated. Referral rates differed significantly (p<0.001) between the usual care (without screening questionnaires) and prospective (with screening questionnaires) arms. Conclusion: The routine use of a screening questionnaire improves significantly the detection and referral rate to CGS, based on consensus criteria, of individuals that may be at risk of hereditary cancer of the breast, ovaries, and/or uterus, and may benefit from professional genetic counselling and testing. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B11.