Forty-eight of fifty-four patients who had had closed reduction and percutaneous pinning of an unstable fracture of the proximal end of the humerus were available for clinical and roentgenographic follow-up at an average of three years (range, two to seven years) after the operation. According to the point-scale of Saillant et al., the result was good or excellent in thirty-four patients, fair in ten, and poor in four. Four patients had loss of fixation and had repeat fixation with percutaneous pinning after a second closed reduction. Only one of them had a poor result because of malunion. Four patients had a superficial pin-track infection and loosening of pins, one patient had a deep infection, and two had a non-union. Complete avascular necrosis with collapse of the humeral head developed in only two patients. However, eight patients had localized avascular necrosis with transient cyst formation and sclerosis in the humeral head that resolved over one to two years; these were thought to represent subtotal avascular necrosis. Although closed reduction and percutaneous pinning is a technically demanding procedure, it offered results in our patients that were comparable with or superior to those after previously described operative methods for the treatment of unstable fractures of the proximal end of the humerus.