We conducted a prospective study of an electronic clinical reminder system in an academic medical center-based human immunodeficiency virus (HIV) specialty clinic. Published performance indicators were used to examine adherence to HIV practice guidelines before and after its implementation for 1204 patients. More than 90% of patients received CD4 cell count and HIV type 1 (HIV-1) RNA level monitoring every 3-6 months during both time periods, and approximately 80% of patients with a CD4 cell count nadir of <350 cells/mm(3) received highly active antiretroviral therapy. Patients were significantly more likely to receive prophylaxis against Mycobacterium avium complex (hazard ratio, 3.84; 95% confidence interval [CI], 1.58-9.31; P=.003), to undergo annual cervical carcinoma screening (OR, 2.09; 95% CI, 1.04-4.16; P=.04), and to undergo serological screening for Toxoplasma gondii (odds ratio [OR], 1.86; 95% CI, 1.05-3.27; P=.03) and syphilis infection (OR, 3.71; 95% CI, 2.37-5.81; P<.0001). HIV clinical reminders delivered at the time that HIV care is provided were associated with more timely initiation of recommended practices.