The causes and outcome of cardiopulmonary arrests were studied in a paediatric hospital over a 12 month period. Forty five resuscitation attempts were made involving 41 children and one adult. Twenty eight (68%) of the children were under 1 year of age and 10 (24%) were neonates. Twenty one (47%) arrests were primarily respiratory and 11 (24%) primarily cardiac in origin. Eighty two per cent of the respiratory arrests had an initially successful outcome, compared with 36% of the cardiac arrests. Overall 70% of cardiopulmonary resuscitation attempts were initially successful. There were no survivors from resuscitation attempts longer than 30 minutes. At 12 months after cardiopulmonary resuscitation 15 (37%) of the children were still alive. The 11 children who had been neurologically normal before the arrest showed no evidence of neurological damage after successful cardiopulmonary resuscitation.