The objectives of this study were to evaluate recent trends in the frequency and length of stay of hospitalization for asthma in the province of Quebec and to estimate the costs of asthma hospitalizations. Data were extracted for persons hospitalized for 30 days or less with a primary diagnosis of asthma in all Quebec short-stay hospitals during the years 1988/89, 1989/90 and 1994/95. There were 1.76 asthma hospitalizations per 1000 persons in Quebec in 1988/89, down to 1.44 in 1989/90 and up again to 1.75 in 1994/95. There was a small decrease in mean length of stay when the three data years were compared. In all three years, the rate of hospitalization was particularly high among young boys. In 1994/95, more hospitalizations occurred during the fall months. We estimated the total cost for asthma hospitalization that year to be $18 to $21 million.