Genetic counseling and testing for heritable susceptibility to breast cancer caused by mutations in BRCA genes are largely unavailable to underserved women in the United States. Starting in 2002 the UCSF Cancer Risk Program offered this service free of charge to poor and medically indigent women at San Francisco General Hospital (SFGH). One recruitment strategy was a single-page questionnaire in four languages administered to women waiting for mammograms at SFGH. This report analyzes our first 3 years of experience with the recruitment questionnaire and compares the patient demographics and BRCA test results at SFGH with a more typical population undergoing genetic counseling and testing at UCSF's Mt. Zion Hospital (MZH). To our knowledge this is the first comprehensive clinical service for hereditary breast cancer in a U.S. public hospital. The ethnic mix of all 350 patients counseled was Caucasian 49% (approximately 20% of Caucasians reported Ashkenazi Jewish ancestry), Latina, 26%; African American, 13%; and Asian/other, 12%. Compared to the MZH population, SFGH patients were more ethnically diverse, less educated and more likely to be unemployed. Of 72 patients tested for BRCA mutations, 51 (71%) were negative, 5 were BRCA1 positive, and 12 were BRCA2 positive. Four (1 Caucasian, 1 Latina, 2 African American) had a total of 13 BRCA variants of unknown significance (VUS). The ratio of BRCA1/BRCA2 positive SFGH patients (5/12) was reversed compared to MZH (119/91). We evaluated 4573 recruitment questionnaires and 280 (6%) were judged to represent a high risk of heritable cancer. After additional screening and referral negotiation, 74 were scheduled for counseling. We judged the recruitment questionnaire to be a feasible, efficient, and reasonably cost-effective way to identify women at high risk of hereditary cancer in a traditionally underserved population. Underserved populations present special challenges for genetic counselors because of large, geographically dispersed families, cultural taboos about cancer diagnoses, and social marginalization. Despite these complexities, the clinical service at SFGH has been well accepted by patients and staff. Our successful venture can serve as a model for other public hospitals contemplating this clinical service.