Background: Despite the significant associated morbidity of necrotizing fasciitis (NF), few studies have been published and this is the larger pediatric series in Latin America. Aim: To describe the epidemiology, clinical characteristics and microbiology of NF in Costa Rican children. Methods: Review of clinical and pathological records, period April 2002 to April 2014, in patients under 13 years of age. Results: 19/22 patients met the inclusion requirement, 12 had co-morbidity: 26% with a history of recent surgery and 21% were neonates. Etiology was documented in blood cultures in 26% and by tissue culture in 63% (one third of them polymicrobial). Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the three most common etiologic agents. Case fatality rate was 42%, one of the highest in our region. Conclusion: NF is a serious, unusual pathology, frequently associated with neonatology and post-surgical patients, with a mixed etiology that requires the association of antimicrobials and early surgery. Its lethality is high in our setting, over previously published series.