As the basis for this paper, it must be acknowledged that children are not simply small adults. But this acknowledgment must go further: infants are not simply small adolescents. As data for pediatric mechanical ventilation, in general, and the management for pediatric acute lung injury, more specifically, are very limited, the pediatric critical care clinician must closely assess the available adult data and evaluate its application for infants and children. Given the hurdles in studying pediatric acute lung injury and acute respiratory distress syndrome, clinicians involved with the care of critically ill infants and children are left with extrapolation of data from the neonatal and adult populations, reliance on the limited available pediatric data, careful assessment of the applicable physiologic and pathophysiologic principles, and/or reliance on their own experience and their colleagues' experience. Hopefully, with the collaboration of multicenter investigator networks, additional and definitive pediatric data may be on the horizon. In the meantime, sharing data between adult and pediatric populations seems to be an essential approach to the management of critically ill patients.