Abstract: A pneumatic nailer having a safety mechanism that reduces accidental discharge of nailer is provided. The nailer includes a hollow main body housing having a main pressure chamber in pneumatic communication with a main valve housing. Pressurized gas is injected into main pressure chamber, and a metering hole between the main chamber and valve assembly allows gas pressure to equalize between the main chamber and the valve housing. A safety trigger and safety valve are in pneumatic communication with the pressurized valve housing. A ram cap positioned over the top portion of the valve assembly is struck, moving the main valve assembly downward, with unseating of a cylinder firing valve only if internal pressures have been adjusted by actuation of the safety valve by an operator.