A comparison study of synthetic nonabsorbable suture (nylon or Prolene) with absorbable suture (Dexon-S or Vicryl) for bronchoplasty was performed in growing puppies. The experiments (n = 15) were followed up for 185 to 381 days (average 323.8 days). Bronchoscopic and bronchographic studies were done at intervals. No stenosis was observed in the group receiving absorbable suture (n = 8), and the anastomoses grew proportionately with the proximal and distal bronchi. In the group receiving nonabsorbable suture (n = 7), variable stenoses developed; two moderate and two severe stenoses were observed during the early healing stage by bronchoscopic examination. In the sequential bronchograms, an increase of stenosis was noted in two dogs. The results suggest that absorbable suture is superior to nonabsorbable suture in pediatric bronchoplasty.