Bilevel positive airway pressure therapy (bilevel therapy) is a useful tool for noninvasive ventilation in a pediatric intensive care unit (ICU). The objective of this study was to evaluate use of bilevel therapy in a tertiary care pediatric ICU by retrospective chart review. All patients during the study period (April, 2000, to June, 2003) who received mechanical ventilation were included (189 total): 94 received bilevel therapy (group 1) and 95 underwent invasive mechanical ventilation during the same time (group 2). None were excluded. A database was developed and analyzed. Data between groups were analyzed using t test and chi-square. Mean age of total sample was 9.20 years ± 5.536 SD; mean weight, 26.49 kg ± 16.68 SD. Mean age of group 1 was 10.87 yrs ± 0.50166 SD; mean weight, 30.46 kg ± 17.490 SD. A higher number of patients treated with bilevel therapy had acute respiratory failure (ARF) of infectious etiology or postoperative respiratory failure compared with primary airway compromise or ARF associated with other organ system dysfunction (p = 0.0001.) Patients with cerebral palsy, spinal muscular atrophy, or muscular dystrophy received bilevel therapy (p = 0.001, 0.034, and 0.013, respectively). Patients with postoperative respiratory insufficiency received bilevel therapy (p = 0.022). Mean age of group 2 was 7.55 years ± 5.584 SD; mean weight, 22.57 kg ± 14.91 SD. Group 2 had higher incidence of more than one organ system dysfunction (p = 0.019). Nosocomial tracheitis or ventilator-associated pneumonia were prevalent in group 2 (p = 0.020). We believe bilevel therapy is successful in older, heavier patients who have an acute respiratory infection or postoperative respiratory distress or insufficiency, with an underlying diagnosis of cerebral palsy or muscle disease. Those with ARF combined with other organ dysfunction required invasive mechanical ventilation.