The treatment of 64 intra-articular fractures at the base of the fifth metacarpal was studied. 11 fractures with minimal displacement had been immobilised in a plaster cast without reduction. The position was improved in five of 25 fractures treated by closed reduction and a plaster cast, six of nine fractures after percutaneous pinning, and 12 of 19 fractures after open reduction and internal fixation. At follow-up after a median of 4.3 years, 19 of 50 patients answering a questionnaire had intermittent pain, especially on firm grip. 43 patients were re-examined clinically and radiographically: 21 (49%) had decreased grip power, and 28 had radiographical signs of osteoarthrosis.