Abstract: A transmission shift interlock device which prevents a motor vehicle operator from shifting the automatic transmission shift lever out of the park or neutral position unless some action such as the brake pedal being depressed is taken. The device provides interlock capability by locking the transmission shift cable. An in-line solenoid is provided within the shifter cable having a movable armature which, when energized, forces locking balls or other engagement features into interlocking engagement with the cable core or rod member attached thereto. An alternate embodiment provides an adjustment link for accommodating vehicle tolerance variations and further provides means for having interlock capabilities at more than one shifter position.