Even though certain health needs of gay, lesbian, and bisexual (GLB) patients are unique and different from those of the heterosexual patient, physicians do not usually ask patients about their sexual orientation. This study investigates family physicians' common practice regarding their patients' sexual orientation. Most of the physicians surveyed knew of less than 0.5% GLB patients in their practice; 44.4% did not know of any GLB patients. Only one physician commonly asked his patients about their sexual orientation; other physicians rarely or never asked. Asking patients about their sexual orientation significantly (P < 0.01) predicted the number of GLB patients known to the physician. Asking about patients' sexual orientation is not a common practice for family physicians, and, thus, they are usually unaware of the GLB patients in their practice.