Abstract: A garage door opener security system, for preventing the unauthorized opening of a garage door, mounted within a dwelling. The garage door opener has a track mounted to the dwelling, and a truck slidably mounted on the track which is operatively engaged with the door. A release lever extends downward from the truck to allow manual release and opening of the garage door. The security system prevents unauthorized operation of the release lever by providing a pair of security plates which extend downward from the truck on either side of the release lever. The security plates thereby prevent an unauthorized person from extending an object into the garage from outside in an attempt at operating the release lever.