We have found that fentanyl delivered by PCA provides an effective alternative when adverse effects occur with other more frequently used narcotics. Although anecdotal experience exists concerning the use of fentanyl PCA in adults, dosing guidelines in children must depend on consideration of the current narcotic regimen and the use of equipotent doses of fentanyl. Our initial experience suggests that this is a safe and reliable technique; however, until prospective studies further delineate dosing guidelines, close observation (continuous pulse oximetry and hourly checks of respiratory rate) of these patients is recommended. With such caveats, fentanyl PCA appears to provide an acceptable alternative to "more conventional" narcotics.