In a bone cement mixing and delivery device, a plug can be removably disposable in an injection passage of a cylindrical container. A mixing screw can rotate in a chamber of the container and has a screw thread extending along an outer surface of the mixing screw as well as a return passage extending through the mixing screw from the proximal end to the distal end thereof. In a mixing mode of the device, a mixing rod engages and rotates the mixing screw about a longitudinal axis of the cylindrical container causing material disposed in the chamber to be moved distally and return to the proximal end of the chamber through the return passage of the mixing screw. In an injection mode of the device, the plug can be removed from the injection passage and an injection rod occludes the return passage of the mixing screw.