The authors report a group of 73 cases of fractures of the base of the first metacarpal treated between 1974 and 1989. Fifty-three articular fractures (73%) and 20 non-articular fractures are described. Sixty-eight patients were treated surgically: 49 diverging pin insertions were used, 15 Lars Thoren technique, 5 rigid osteosyntheses with AO miniaturized material. Forty-two patients were seen again after one year or more. We classify the results as follows: very good: 29 (69%), good: 10 (24%), bad: 3 (7%). The relative simplicity, the reliability and the good results of the double diverging pin insertion lead the authors to apply this method in most fractures of the base of the first metacarpal, either articular or extra-articular.