OBJECTIVE To assess inhalation technique in patients after written instruction alone, written and verbal instruction, and clinical use of two new inhalation devices. METHODS Randomized, crossover evaluation of the albuterol Diskhaler and the terbutaline Turbuhaler. METHODS Canadian tertiary-care hospital. METHODS Twenty hospitalized adults with asthma or chronic obstructive pulmonary disease currently using an albuterol metered-dose inhaler (MDI). Nineteen patients received Diskhaler, 16 received Turbuhaler, 15 received both inhalers, and 10 patients used both inhalers for three days each. METHODS Patients were randomized to receive either Diskhaler or Turbuhaler for three days. Inhaler technique was assessed after written instruction, written plus verbal instruction, at the first scheduled dose after instruction, and after three days of clinical use. Patients remaining in the hospital after three days crossed over to the other study inhaler and the same protocol was followed. METHODS Patient inhalation technique was assessed and compared for the MDI, Diskhaler, and Turbuhaler. RESULTS Assessment of MDI technique revealed that 35 percent of patients used their MDI correctly on the first puff, and 42 percent used it correctly on the second puff. Following written instruction alone, correct technique was demonstrated by 32 percent of patients with Diskhaler and 6 percent with Turbuhaler. Technique significantly improved following verbal instruction, although 40 percent of the patients required up to three attempts to demonstrate correct technique on at least one of the study inhalers. After three days of clinical use, correct technique was demonstrated in only 54 percent of the Diskhaler and 64 percent of the Turbuhaler assessments. Performance at this assessment was, however, significantly better on the Turbuhaler than on the MDI (p = 0.01). Performance on the Diskhaler was not significantly different from the performance on the other inhalers. CONCLUSIONS Written instruction alone is inadequate in teaching correct inhalation technique. Verbal instruction and technique assessment are essential for patients to achieve proper technique. Patients may perform better on the Turbuhaler than on other inhalation devices.