Abstract: An improved pistol holster features lock-in means to prevent removal of the gun from the holster by an unauthorized person or by fall or other unexpected movement of the wearer of the holster. A pin attached to a flexible strap or flap on the outer wall of the holster extends through the trigger guard of the pistol and the end of the pin is captured in holding means fastened to the inner wall of the holster. Thus, the locked-in pistol cannot be withdrawn from the holster without first pulling the strap to separate the pin from the holding means.