Abstract: A door security assembly comprises a generally U-shaped striker plate member for fitting transversely around one side edge of a door frame and having a first arm for facing into the door opening having an opening for receiving a door latch, and a second, parallel arm for fitting between the door frame and the surrounding doorway in the wall. The striker plate member is secured to the doorway in the wall by means of a securing device which extends transversely through the first arm, door frame and second arm into a stud member in the surrounding doorway. Additional reinforcement may be provided by a tie plate which is secured to an outer wall surface and extends between the door frame and second arm, the securing device extending through both the striker plate member and tie plate.