OBJECTIVE: This study compares substance use by medical specialty among resident physicians. METHOD: The authors estimated the prevalence of substance use of 11 medical specialties from a national sample of 1,754 U.S. resident physicians. RESULTS: Emergency medicine and psychiatry residents showed higher rates of substance use than residents in other specialties. Emergency medicine residents reported more current use of cocaine and marijuana, and psychiatry residents reported more current use of benzodiazepines and marijuana. Contrary to recent concerns, anesthesiology residents did not have high rates of substance use. Family/general practice, internal medicine, and obstetrics/gynecology were not among the higher or lower use groups for most substances. Surgeons had lower rates of substance use except for alcohol. Pediatric and pathology residents were least likely to be substance users. CONCLUSIONS: The authors' previous research indicates that residents overall have lower rates of substance use than their age peers in society. Yet resident substance use patterns do differ by specialty. Residents in some specialties are more likely to use specific classes of drugs, to use a greater number of drug classes, and to be daily users of alcohol or cigarettes.Abstract Teaser