A pneumatic impact tool includes a housing, an accumulation chamber, and a piston. The housing defines a longitudinal passageway with a rear end and a front end and a passageway gas port. The accumulation chamber has a accumulation chamber gas port connectable to a gas supply and a inner gas port in fluid communication with the longitudinal passageway. The piston is inserted in the longitudinal passageway and slides between a rest position wherein the piston is juxtaposed to the rear end of the longitudinal passageway and an impact position wherein the piston is juxtaposed to the front end of the longitudinal passageway. The piston moves from the rest position to the impact position when gas is inserted in the longitudinal passageway through the passageway gas port and is propelled therebetween by pressurized gas contained in the accumulation chamber.