The Walther PPQ is not a true new design. It shares its engineering principles and main features with the Walther P99QA variant of the P99 pistol that was introduced in 1996.Many modifications compared to the Walther P99QA like the re-designed grip, trigger guard and slide with forward serrations made their combined appearance in 2008 in the Walther P99 RAD, a P99 variant made in Poland and marketed as a military sidearm proposition and the Walther P99Q police pistol.
Due to product evolution the PPQ maintains compatibility with both P99 sights and P99 second-generation magazines and other accessories
The main innovation of the PPQ over the P99QA, P99 RAD and P99Q is its 'Quick Defense' trigger.