The frame of the Ruger 57 is what the company describes as High-Performance Glass-Filled Nylon while the slide and barrel are both Alloy Steel, the former finished in Black Oxide and the latter in Black Nitride. The grip is finely textured for a secure hold, although recoil is exceptionally mild and the slide has cocking serrations both front and rear.

The barrel has a 1:9 right-hand twist with eight grooves. With a weight of only 24.5 oz., the Ruger is very easy to carry in a properly designed holster. Rather than being a striker-fired pistol, this Ruger features an internal hammer with an ambidextrous thumb safety. Ruger calls this the Secure Action Fire Control. There is also an inspection port allowing one to tell if the chamber is loaded. The trigger is excellent with a short, crisp pull and a positive reset. Two 20-round steel magazines are provided and the frame is fitted with an easily accessible, reversible magazine release that also operates positively to allow the magazines to easily drop free.