A dispensing gun includes a housing for holding a cartridge, a push rod engaged through the housing and having a plunger for engaging with the cartridge, an actuating plate engaged onto the push rod, a trigger pivotally secured to the housing and having an actuating pin for operating the actuating plate to move the push rod relative to the housing, a spring member biasing the actuating plate to engage with the actuating pin of the trigger, a latch engaged onto the push rod and biased to prevent the push rod from moving rearwardly relative to the housing when the actuating plate is released by the trigger, and a release member is located between the latch and the actuating pin of the trigger for being moved to release the push rod from the latch.
