We report a case of septic dislocation of the hip in an eight-month-old infant secondary to BCG vaccination. The usual treatment of septic arthritis with surgical drainage and broad spectrum antibiotics was unsuccessful. Cure was achieved after institution of an anti-tuberculosis treatment and a second surgical drainage. This rare complication of BCG vaccination can develop several months after administration of the vaccine. Diagnosis is often difficult to establish due to the minimal clinical and non-specific clinical expression. Early radiological signs are also non-specific. Identification of the causal agent can be most difficult. Certain diagnosis is generally achieved after biopsy and pathology examination. Despite the attenuated virulence of the vaccine, anti-tuberculosis treatment is indispensable to achieve cure. Surgery drainage alone is insufficient.