Background-Pediatric cardiopulmonary resuscitation (CPR) for >20 minutes has been considered futile after pediatric inhospital cardiac arrests. This concept has recently been questioned, although the effect of CPR duration on outcomes has not recently been described. Our objective was to determine the relationship between CPR duration and outcomes after pediatric in-hospital cardiac arrests. Methods and Results-We examined the effect of CPR duration for pediatric in-hospital cardiac arrests from the Get WithThe Guidelines--Resuscitation prospective, multicenter registry of in-hospital cardiac arrests. We included 3419 children from 328 US and Canadian Get With The Guidelines-Resuscitation sites with an in-hospital cardiac arrest between January 2000 and December 2009. Patients were stratified into 5 patient illness categories: surgical cardiac, medical cardiac, general medical, general surgical, and trauma. Survival to discharge was 27.9%, but only 19.0% of all cardiac arrest patients had favorable neurological outcomes. Between 1 and 15 minutes of CPR, survival decreased linearly by 2.1% per minute, and rates of favorable neurological outcome decreased by 1.2% per minute. Adjusted probability of survival was 41% for CPR duration of 1 to 15 minutes and 12% for >35 minutes. Among survivors, favorable neurological outcome occurred in 70% undergoing <15 minutes of CPR and 60% undergoing CPR >35 minutes. Compared with general medical patients, surgical cardiac patients had the highest adjusted odds ratios for survival and favorable neurological outcomes, 2.5 (95% confidence interval, 1.8-3.4) and 2.7 (95% confidence interval, 2.0-3.9), respectively. Conclusions-CPR duration was independently associated with survival to hospital discharge and neurological outcome.Among survivors, neurological outcome was favorable for the majority of patients. Performing CPR for >20 minutes is not futile in some patient illness categories.