A security product display hook assembly comprising a unique form of product display hook, in combination with a security lock, providing optional levels of product security and customer convenience. The display hook has a merchandise supporting arm formed with a back section, an intermediate section and a front section. The intermediate section is of sharply irregular configuration to allow, but inhibit, product removal, while effectively preventing mass product removal often attempted by shoplifters. The locking device is positionable in front of or directly behind the intermediate section to provide the highest security, with all products locked or an intermediate level, with a portion of the products locked. The locking device can also be positioned at the back of the back section such that all products are unlocked and available for customer selection.