We reviewed 82 consecutive hospital admitted patients treated for acute severe asthma over a seven-month period at a University medical center and an additional 25 patients at an affiliated community hospital. Those asthmatics treated on the adult medical service had a significantly longer length of hospitalization when compared to those treated on the pediatric service (t = 5.12; p less than 0.005). In addition, longer hospitalization periods were noted for those asthmatics who smoked (t = 2.98; p less than 0.005) and for those with a history of chronic bronchitis (t = 2.32; p less than 0.025). Drug regimens were frequently suboptimal; 30% of the patients reviewed were receiving no therapeutic agents prior to admission. Of those patients receiving theophylline 53% had serum levels of less than 10 mcg/ml on their post admission assessment. Although frequently suboptimal, inadequate drug regimens prior to admission did not lengthen hospital stay. Poor compliance with medications was recorded as a major cause of decompensation in nine patients whose mean age was 13 years. Finally, occupational exposure to airway irritants was elicited from 24% of the adult population at the University medical center. Increased length of stay in the hospital for adult asthmatics may reflect relatively fixed airway disease among these patients since a significant proportion of them related a history compatible with chronic bronchitis or were smokers. Occupational histories should be evaluated in adult asthmatics to rule out workplace exposures as a cause for severe decompensation. In addition, the importance of educational efforts addressing therapeutic non-compliance is evident from this study.