Historically, bacterial infections were categorized as either community-acquired (CA) or hospital-acquired (HA). However, the CA/HA dichotomy no longer adequately reflects patterns of emerging healthcare-associated (HCA) infections in complex patients managed between hospital and the community. Studies trying to define this evolving epidemiology often excluded children. To identify what criteria have been used to distinguish between CA, HCA and HA bloodstream infections (BSIs) in children, and the proportional distribution of CA, HCA and HA among total BSIs and by organism. We systematically reviewed published literature from PubMed, UK Department of Health and US Centers for Disease Control and Prevention websites. Results from 23 studies and the websites highlighted the use of inconsistent criteria. There were 13 and 15 criteria variations for CA and HA BSI respectively, although a 48h cut-off for cultures sampled post admission was most commonly reported. Five studies used variable clinical criteria to define HCA. The mean proportion of paediatric CA BSI in nine studies was 50%. Only four BSI organisms from five studies were predominantly CA (Streptococcus pneumoniae, Salmonella spp.) or HA (coagulase-negative staphylococci, Enterococcus spp.), whereas Pseudomonas spp., Klebsiella spp. and Enterobacter spp. did not clearly fit into either category. Our study reveals inconsistent use of criteria, and a lack of evidence upon which to base them, to distinguish between CA, HCA and HA BSI in children. Criteria for CA, HCA and HA BSI need to be developed using population-based studies that consider patients' clinical characteristics, recent healthcare exposure as well as isolated organism species. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.