The aim of this study is to examine how physicians use clinical practice guidelines that call for routine HIV screening in a general adolescent medicine clinic and to determine how adolescent patients respond to routine screening. Physicians offered screening to 116 of 217 patients (53%) aged 13-21 who completed a survey. Physicians' offers conformed to the latest Centers for Disease Control and Prevention (CDC) guidelines with 73% of patients because some patients not offered a test had been screened within the last year. Physicians were three times more likely (OR = 3.0; 95% CI = 1.3-6.8) to offer HIV screening to sexually active adolescents than to adolescents who reported no sexual history. Adolescent medicine physicians and their patients endorse the idea of routine screening as embodied in the latest CDC recommendations, but adolescents with no sexual history are less likely than other adolescents to accept screening when it is offered and to support a clinic policy of routine screening. Both physicians and their adolescent patients continue to test based on risk assessments.