The authors report 13 cases of osteoarticular infection observed during the first month of life. The origin was iatrogenic in 7 cases. The diagnosis was based on local inflammatory signs and standard X-ray. The joints most often affected were the hip (8 out of 19 localizations) and the ankle (5/19). The causative bacteria was mostly isolated from blood culture (10/13 cases) and was staphylococcus aureus in 11 cases. Treatment included prolonged antibiotic-therapy for 1-4 months, plus evacuation by joint punctures and immobilization of the affected limb with a plaster or traction. Functional sequellae were observed in 3 children and essentially concerned the hip.