BACKGROUND: Current knowledge of clinical features of imported childhood malaria is largely limited to small, retrospective, and/or single-center case series. This prospective, population-based study describes the epidemiology and clinical features of imported childhood malaria in children <16 years in the United Kingdom and Republic of Ireland. METHODS: Active prospective national surveillance with clinical data collection was performed between January 1, 2006 and January 31, 2007 through the British Pediatric Surveillance Unit and capture-recapture analysis using cases reported independently to respective national surveillance centers. RESULTS: There were 290 cases, including 186 reported through the British Pediatric Surveillance Unit with clinical details. Capture-recapture analysis estimated the burden of imported childhood malaria to be 2.8/100,000 per year for the United Kingdom and 4.6/100,000 per year for Ireland. Black-African children born in the United Kingdom and Ireland and traveling to West Africa during school holidays without antimalarial prophylaxis accounted for the majority of cases. Thirty of 117 children (26%) who had traveled to a malaria-endemic country had previously been diagnosed with malaria, reflecting missed opportunities to educate families on malaria prevention. A third of children (46/148) with Plasmodium falciparum malaria fulfilled World Health Organization criteria for severe or potentially complicated malaria, although only 11/46 (24%) required intensive care. The choice of antimalarials varied considerably among hospitals and within the same hospital. However, recrudescence occurred in only 1 child and none died. CONCLUSIONS: Interventions to prevent imported childhood malaria should focus on Black-African families traveling to West Africa, while pediatricians should be offered clearer guidance on the treatment of childhood malaria.