Abstract: A door lock drill assembly includes a housing with an apertured side wall and end wall, securable upon the upright edge of a door for drilling a first aperture through the door on a first axis and successively drilling a second aperture into the door edge on second axis coplanar to and at right angles to the first axis. Guides are mounted upon the side wall and end wall and extend at right angles thereto. A hole saw is reciprocally mounted upon one guide coincident with the first axis, and includes a projecting coaxial drill shaft. A drill bit is reciprocally mounted upon the other guide coincident with the second axis, and includes a projecting coaxial drill shaft. The drill shafts are adapted to be selectively and alternately power driven and fed into the door by the application thereto of a power driven tool.