Osteo-articular tuberculosis is rare in infants. The MRI findings reported for adolescents and young adults mainly relate to spinal involvement. Two cases of osteo-articular tuberculosis of infants located at the knee are presented. Vaccination has been correctly done. Skin test and chest radiography were normal. Evolution was insidious for one case. Osseous, medullary, cartilaginous and soft tissue abnormalities revealed by MRI were suspicious for tuberculosis. Diagnosis was confirmed at histology for both cases and bacteriology for one case. The aim of this study is to report the MRI features of osteo-articular tuberculosis in pediatric patients.