This study reports the results of Swanson replacement of 131 DIP joints for painful osteoarthritis and two for ongoing pain after injury. Thirty-seven arthroplasties (28 patients) were carried out with extensor tendon division and repair, and postoperative immobilization for 8 weeks. Ninety-four (60 patients) were then carried out without tendon division, allowing immediate mobilization. At assessment after a mean period of 57 months, the mean postoperative range of movement was 39°, and the mean extensor lag was 11°, with significant improvement of both in both operative groups. The severity of pain improved significantly following surgery. All but one patient were satisfied with the cosmetic result of replacement. The overall complication rate was 7/131(5%). Three joints developed cellulitis and one developed osteomyelitis, requiring subsequent fusion. Two joints had subsequent fusions because of persistent lateral instability and marked ulnar deviation and one had a persistent mallet-type deformity, corrected by tendon shortening.