A biopsy marker deployment device adapted to selectively deposit a marker in a target location, such as a biopsy site. In one embodiment, the device includes a deployment assembly comprising a cannula adapted to house at least one marker, an outlet aperture defined by a portion of the cannula, and an actuatable pushrod slidably disposed and movable within the cannula. The deployment assembly further comprises a selectively opening outlet door movable between an open position and a closed position. The outlet door is biased in the closed position and at least partially obstructs the aperture in the closed position to prevent a marker from reentering the cannula upon deployment.