Chronic tenosynovitis of the hand due to Mycobacterium tuberculosis has become rare. In the two cases presented here, the final diagnosis was obtained by isolation of the organism in the intercarpal fluid (1 case), or by a synovial biopsy (1 case). Ultrasonography showed a hypoechoic thickening of one or several tendon sheaths. MR enabled better differentiation between the thickening of the synovium itself and a fluid effusion. The criteria permitting to differentiate tuberculous from non-infectious tenosynovitis are: young age, male sex, specific epidemiological factors, elevated erythrocyte sedimentation rate, marked local swelling, association with other foci of tuberculosis, unusual exudation and synovial thickening, and association with osteitis.