Although numerous retrospective studies have attempted to investigate the incidence, etiology, and pathogenesis of subglottic stenosis, there have been few prospective studies. The retrospective studies focused initially on diagnosed cases, then drew inferences regarding incidence and causality based upon data obtained from review of patient records. In contrast, this prospective study accrued data on all neonates intubated for 48 hours or longer during the 1-year intake period. There were 195 neonates entered in the study; then 36 were excluded, leaving 159 for data analysis. Parameters assessed included age at intubation (mean, 5.7 days), duration of intubation (mean, 12.3 days), and number of times reintubated (mean, 0.79). Results of this prospective study are compared to results from previous retrospective studies.