Abstract: A trimming and piercing apparatus of an extremely high operation efficiency which is capable of trimming and piercing a work simultaneously. The apparatus comprises a fixed die provided with a work mounting surface and a piercing bore opened at the work mounting surface, and a movable die displaceable toward and away from the fixed die. A pair of movable blades and a pair of fixed blades are provided in a spaced opposed relation on the movable die and the fixed die, respectively, so that the movable blades are engageable with said fixed blades when the movable die is moved toward the fixed die. A cam slide having a piercing punch is slidably mounted on the movable die. A cam driver is mounted on the fixed die for driving the cam slide to move along the movable die toward the fixed die to place the piercing punch into fitting engagement with the piercing bore in the fixed die as the movable die is displaced toward the fixed die.