The aim of the study was to evaluate the results of treatment of osteoarthritis of the carpometacarpal joint of the thumb with tendon allograft interposition. Fifty-three patients (61 hands), 13 men and 40 women, were operated on at a mean age of 61 years. A partial trapeziectomy with tendon interposition was performed in 19 hands and with suspension arthroplasty in 24. Seventeen thumbs underwent a total trapeziectomy with suspension arthroplasty. Patients were evaluated at a mean follow-up of 4 years. In 34 patients (41 hands), a mean disability of arm, shoulder and hand score of 19 was found and a mean visual analogue scale for pain of 1.3. The satisfaction rate was 83 %. Revision operations were performed in 8 out of 61 hands. Four of those thumbs had been operated on previously or did not have primary osteoarthritis. No revisions were needed after partial trapeziectomy and tendon allograft interposition with suspension arthroplasty. In conclusion, tendon allograft interposition can be considered as one of the treatment options for osteoarthritis of the carpometacarpal joint of the thumb.