Self-reported past year use of alcohol, tobacco, marijuana, cocaine, and two controlled prescription substances (opiates, benzodiazepines); and self-reported lifetime substance abuse or dependence was estimated and compared for 12 specialties among 5,426 physicians participating in an anonymous mailed survey. Logistic regression models controlled for demographic and other characteristics that might explain observed specialty differences. Emergency medicine physicians used more illicit drugs. Psychiatrists used more benzodiazepines. Comparatively, pediatricians had overall low rates of use, as did surgeons, except for tobacco smoking. Anesthesiologists had higher use only for major opiates. Self-reported substance abuse and dependence were at highest levels among psychiatrists and emergency physicians, and lowest among surgeons. With evidence from studies such as this one, a specialty can organize prevention programs to address patterns of substance use specific to that specialty, the specialty characteristics of its members, and their unique practice environments that may contribute risk of substance abuse and dependence.