The prognosis for the fetus or neonate with asplenia syndrome is unknown as population-based data are unavailable. Factors influencing survival in this syndrome were, therefore, assessed for the province of British Columbia by retrospective review of all cases diagnosed between 1970 and 1990. Particular attention was paid to the prognostic influence of palliative surgery, sepsis, extracardiac malformations, gastrointestinal disease, arrhythmias and sudden death. We identified 43 cases of asplenia syndrome, of which 40 were live-born (incidence 1/22,000 live‐births). Only one spontaneous death was noted during fetal life amongst approximately 5,000 fetal autopsies. Five cases had been diagnosed by fetal echocardiography, two of these pregnancies being terminated. Of the live-born infants, 28 (70%) underwent active management of their cardiac anomalies and of these, 14 are alive. Since 1980, 26 systemic-to‐pulmonary shunts have been constructed in 17 children with two operative deaths. Three children have had successful Fontan or bidirectional Glenn procedures. Systemic sepsis occurred in three children with no deaths. Three neonates underwent surgery for obstruction of the upper gastrointestinal tract without complication. Late sudden death occurred in four children with systemic-to-pulmonary shunts, none of whom had documented arrhythmias. Major extracardiac malformations were present in nine cases (21%), these contributing to death in two. Overall survival for all live-born infants is 35%. Sepsis and palliative surgery are no longer the major causes of death in asplenia syndrome, the current challenges being prevention of sudden death and the complexity of surgical repair of the cardiac malformations.