A spontaneous tendon rupture is a direct consequence of rheumatoid inflammation and can appear without any noticeable impact, often during sleep. The patient then presents with inability to flex or extend metacarpophalageal or interphalangeal joints. Multiple ruptures resulting in impaired function of several fingers can also occur and markedly limit the hand's grip strength. A tear may arise from either mechanical injury to the tendon along its course over bone or connective tissues, or by biochemical action of lysosomal enzymes, released during the inflammation process, on the connective tissue of the tendon. Ischaemic damage to a part of the tendon due to constriction of vessels supplying the peritenonium is found in hypertrophic peri-tenosynovitis. Spontaneous ruptures can be prevented, in the first place, by early synovectomy and then by a number of prophylactic procedures on soft tissues and carpal bones, which can stop or at least slow down the development of severe axial deformities of the wrist and hand. Simple end-to-end suture of the stumps is usually not possible; tendon repair surgery using free grafts or, more often, intact tendon transfer is necessary. In the flexor part, transfer of the superficial flexor tendon to a stump of the deep flexor tendon is frequently performed; a free graft can also be used at a two-stage tendon reconstruction. The repair of flexor tendons is technically more demanding and the results are less satisfactory compared to repair surgery on the extensor tendon. Key words: rheumatoid arthritis, metacarpophalageal joint, interphalangeal joint, tendon rupture.