Background: As the number ofwomen in medicine and the emphasis on prevention and primary care increase in the United States, it is important to know the extent to which female and male physiciansadvise patients about prevention. It is also important to know whether any gen-$ der-based differences are attributable to women's higher rates of choosing primary care specialties. Prior studies have examined onlysmall populations ofphysicians, lim-ited physician specialties, or few prevention-related out-Methods: Telephone survey from a systematic random sample of the Physician Masterfile maintained by the American Medical Association. One thousand US phy-sicians (167 women and 833 men); a 48% response rate.