This study evaluated British Columbian primary care physicians' use of sexually transmitted disease (STD) and HIV counseling guidelines. The authors sought to assess barriers to integrated HIV and STD testing and counseling, with the objective of developing and revising practice guidelines to meet the needs of primary care physicians in diverse settings. The BC College of Physicians and Surgeons membership of general practice/family medicine practitioners was stratified by practitioner location; 1200 physicians were randomly selected to receive a mailed self-administered questionnaire. Four hundred seven completed questionnaires were returned. Female physicians reported better adherence to practice guidelines on many items than their male counterparts. A minority of primary care physicians routinely integrated HIV and STD testing and counseling. Physicians in nonurban areas were more likely to report that they lacked sufficient information on HIV and STD risk and prevention. Although male primary care physicians in British Columbia were more likely to provide care for people with HIV infection, female physicians were more likely to undertake ongoing screening for sexual risk behavior and sexually transmitted infections (STIs) among their HIV-positive patients. Clinical practice guidelines are theoretically equally available to all physicians, but they are not universally used. Physicians may not receive adequate training in sexual health during their medical education; continuing education opportunities may be limited to physicians outside of urban centres. Accessible and relevant continuing medical education in novel formats are needed to address the gap between ideal and actual practice in HIV and STD prevention, treatment, and care in Canada.