In 120 infants and young children with wheezy bronchitis, pulmonary function examinations were carried out prior to and following inhalation of 1. ipratropium bromide, 2. fenoterol, 3. fenoterol after a prior single administration of prednisone, 4. adrenaline, 5. theophylline administered via a gastric tube, 6. isotonic saline solution. The results show that bronchodilator drugs may be effective in approximately 27% of the patients.