The nall gun is a potentially dangerous device that is commonly used in the construction industry to drive various sizes of nails into wood or concrete. These devices appear to be used without sufficient training and they can be easily obtained by the general publie. We report a series of injuries caused by nail guns. The pattern of these injuries and the mechanism of their production suggest that the safety mechanisms on the guns and the protective clothing worn by operators of the guns do not prevent injuries. We call for a review of operator training and the design of both the safety mechanism of nail guns and the protective clothing worn by operators. If necessary, modifications should be introduced to reduce the likelihood and severity of such potentially serious injuries.