Abstract: A percussive-action pneumatic tool comprising a handle-carrying frame having successively accommodated therein a shock-absorber and a housing with the percussion mechanism therein, connected through a gas distribution system to a compressed air source. The frame has a length sufficient for abutting against the surface of a material being worked and has a guide which receives the housing with the percussion mechanism. The shock-absorber includes a receptacle mounted on the frame and communicating via a controllable valve alternatively with the compressed air source and the atmosphere, a rod being mounted in this receptacle, adapted to act upon the housing with the percussion mechanism, to move the housing relatively to the frame as compressed air is supplied into the receptacle.