A new noninvasive, nonradiographic endotracheal tube (ETT) position detection system (ETT-PDS) for guidance of ETT positioning was evaluated in pediatric ICU patients. The system includes an ETT with a metallic element embedded at a defined distance from the ETT tip, and a portable locator instrument which detects transcutaneously the position of the metallic element. The contribution of ETT-PDS to accuracy of ETT positioning after intubation and before chest radiographs was evaluated in 92 critically ill children. The ETT malposition rates observed on the postintubation chest radiographs were 39.1% after positioning guided by clinical assessment alone, and 19.6% after positioning guided by clinical assessment plus the ETT-PDS (p less than 0.5). This reduction in malnutrition rate could not be demonstrated when the ETT-PDS was used to guide routine ETT positioning performed before morning chest radiographs.