A plunger lock assembly having a removable core is provided. The lock assembly includes a housing defining a first longitudinal bore and a barrel reciprocably mounted within the first longitudinal bore between an advanced position and a retracted position. The barrel defines a second longitudinal bore and is operably associated with a plunger. A core is removable mounted within the second longitudinal bore of the barrel and includes a key slot for receiving an operating key. A drive member is positioned within the second longitudinal bore and is movable from an unlocked position to a locked position by operation of the operating key. A retainer assembly is operably associated with the drive member to axially retain the drive member within the second longitudinal bore such that the core is removable from the second longitudinal bore independently of the drive member. A biasing member is provided for urging the barrel towards the retracted position.