Previous studies have shown that a significant proportion of patients and physicians have difficulty using metered dose inhaler (MDI) delivery systems. It has been suggested that paramedical personnel such as pharmacists could address this problem by serving as patient educators. Few studies have assessed a pharmacist's knowledge of and ability to use inhaled devices, including not only the conventional MDI but newer devices such as an add-on spacing chamber (Aerochamber) and a multidose dry powder inhaler (Turbuhaler). We therefore approached all pharmacists in a predefined geographic area of a large city in order to evaluate their knowledge of and ability to use inhaled medications. Of 62 pharmacists approached, 45 (73 percent) agreed to participate. Ability to use the conventional MDI, Aerochamber (A), and Turbuhaler (T) was graded by a trained observer using a checklist of 11 essential steps. The percentage of pharmacists performing greater than 6, 8, and 10 steps correctly for each device was MDI = 96 percent, 87 percent, 62 percent; MDI + A = 80 percent, 76 percent, 47 percent; T = 67 percent, 64 percent, 29 percent. The most common problems with the MDI were forgetting to shake prior to use and coordinating inspiration with actuation. The most common problems with the MDI + A were forgetting to shake prior to use, remembering to inspire after actuation, and breath holding after inspiration. The most common difficulty with the T was total unfamiliarity with the device with 33 percent of pharmacists achieving less than 2 steps correctly. The observer subsequently administered a questionnaire of 11 clinically relevant questions for each of the devices tested. The mean score was 50 percent with only 21 percent of pharmacists scoring above 70 percent. Thirty-three percent of respondents had no instruction in device use beyond reading the packing insert; 40 percent had received instruction from a pharmaceutical representative; only 24 percent had received instructions from professional school. We conclude that a pharmacist's knowledge of inhaling devices is roughly proportional to the length of time the device has been available and that pharmacists form another group of health care professionals who require further teaching regarding inhaled medication delivery systems.