The efficacy of nebulized budesonide (0.5 mg b.i.d.) against placebo was evaluated in the management of asthma in 23 infants, aged 3 to 17 months, using a double blind crossover design. After an initial treatment period of 2 weeks placebo and budesonide were randomly administered during two consecutive treatment periods of 1 month. The progress of the patients was monitored using diary score cards, the number of salbutamol doses needed during the treatment periods, clinical examinations using standardized scoring cards, and registration of parents' preference period. Although there was a tendency toward fewer wheezing periods during budesonide, the results of the diary score cards were not significantly different between the budesonide period and the placebo period. The number of salbutamol doses used was also the same during both periods. Clinical examination after budesonide revealed less rhinitis and a less pathological lung auscultation, but the difference between the two periods was also not significant. Furthermore, the parents' preference could not distinguish between budesonide and placebo. We conclude that the trends in favor of nebulized budesonide are not significant and do not suggest that the suspension is effective in severe infantile asthma.