Carl Walther Waffenfabrik introduced the Walther PPK, or Polizei Pistol Kriminale, in 1931. In English this would translate roughly to 'Police Detective's Pistol.' It was a follow-on to the Walther PP, introduced two years before. Although numerous semiautomatic pistols (or autoloaders) predated the PP/PPK series, the series contained several safety innovations as well as the first commercially successful double action on a non-revolver handgun. The double action meant that it was possible to safely carry the Walther PPK with the safety off and a round chambered; the initial action meant that an exceptionally firm trigger squeeze was required to 'cock' the hammer for the first shot, but thereafter all shots would fire on single-action until the magazine emptied.

In addition, the PPK had a locking safety that, when engaged, intervened between the hammer and the firing pin. An automatic safety, in addition, locked the hammer action unless the trigger was depressed. There was also a safety interlock called a disconnector which ensured the weapon could not fire unless the slide was completely forward.

This gun was made famous in the non-shooting world by Ian Fleming, who had his famed not-so-secret agent 007 carry one for several books after his trusty Beretta .25 was confiscated by Major Boothroyd and M in Dr. No.

The PPK was hard to find in the United States as it fell afoul of legislation designed to block imports of the small, light guns called 'Saturday Night Specials' in the U.S. Under the rules adopted, the lightweight, reasonably high-power PPK was on the wrong side of the point scaling system. Not until Walther licensed the PPK to Interarms Co. in the U.S. were versions of the pistol widely available. Some have complained about shoddy quality on some American-made versions.

The gun can be chambered for .22 Long Rifle, .32 ACP and .380.