In order to identify factors that influence the outcome from cardiopulmonary resuscitation (CPR) in children, we studied 69 children (mean age 2.5 +/- 0.4 years) who were apneic and pulseless prior to resuscitation, and treated in the Pediatric Intensive Care Unit (PICU) following CPR. Immediate success (restoration of spontaneous circulation and normal sinus rhythm) was noted in 54 (78%) patients. Forty-one (59%) were short-term survivors (greater than 24 h), and ten (14.5%) became long-term survivors (five recovered well, three moderately disabled, and two severely disabled). Fifty-nine (85%) died. Outcome was positively influenced by: 1) CPR duration; when less than five min., 54% were long-term survivors compared to 5% of patients resuscitated for more than five min (p less than 0.001). 2) Number of epinephrine doses: 38% of 24 patients receiving one dose became long-term survivors versus 0% of 26 receiving more than one dose (p less than 0.001). 3) Location of arrest; Fifty percent of patients resuscitated in the operation suite or catherization laboratory survived long-term compared to only 8% resuscitated in the PICU (p less than 0.03). Age, sex, cardiac rhythm, as well as metabolic and acid-base variables during resuscitation, did not significantly affect the outcome. Overall good neurologic survival was rare.