Purpose of the Study: The purpose of this study was to evaluate a diagnostic and management protocol for osteoarticular infection in children which was developed at the Rouen University Hospital in 1993. We studied the technical aspects of the protocol allowing improved certain diagnosis and bacteriological documentation as well as the reduction in intravenous treatments and hospital stay., Material and Methods: Two successive series were compared. The first constituted from May 1984 to February 1992 was a retrospective series of 106 children with osteoarticular infections. The second series was prospective an included 104 children with osteoarticular infection treated after institution of the protocol (January 1995 to December 1998). All children were treated in the same unit. Files were reviewed at a minimum follow-up of 18 months following the end of treatment. We analyzed: clinical, biological, and radiological data at admission; elements of the bacteriological study and their contribution to identification of the causal agent; duration of intravenous antibiotic therapy; total duration of antibiotic therapy, and hospital stay; complications and sequelae., Results: After institution of the protocol, we observed significant progress: certain diagnosis of acute osteomyelitis improved from 67% to 85% after institution of a more comprehensive diagnostic program; bacteriological identification improved from 37.5% to 72.2% for acute osteomyelitis and from 41.6% to 59.5% for septic arthritis, with a growing number of recognized cases of Kingella kingae infections causing acute osteomyelitis (n=2) or septic arthritis (n=4) due to technical progress in sampling and culturing. Mean duration of intravenous antibiotic therapy (15 days versus 9.95 days), mean duration of total antibiotic therapy (47.3 versus 33.8 d) as well as length of hospital stay (17.5 d versus 12.5 d) were significantly improved. The shorter antibiotic therapy did not led to any supplementary morbidity., Conclusions: A systematic bacteriological diagnostic protocol has enabled an improvement in treatment and hospitalization. The protocol has been further updated and simplified in light of these findings and observations of insufficiencies, taking into account recent data in the literature and epidemiological features of osteoarticular infection in children.