[8] The pistol is named for the 5.7×28mm cartridge's bullet diameter, and the trademark's capitalization style is intended to emphasize the manufacturer's initials—FN.

[7] Developed as a companion pistol to the P90, the Five-seven shares many of its design features: it is a lightweight polymer-based weapon with a relatively large magazine capacity, ambidextrous controls, low recoil, and the ability to penetrate body armor when using certain cartridge types.

[16] Sales of the Five-seven were originally restricted by FN to military and law enforcement customers, but since 2004, the pistol has also been offered to civilian shooters for uses such as personal protection and target shooting.

[17][18] Although offered only with sporting ammunition, the Five-seven's introduction to civilian shooters was met with vocal opposition from gun control organizations such as the Brady Campaign, and the pistol has been subject to ongoing controversy in the United States.

[19][20] The Five-seven is currently in service with military and police forces in over 40 nations, including Canada, France, Greece, India, Poland, Spain, and the United States.

[7][27] The Five-seven first entered service in May 2000, when the Cypriot National Guard (Greek: Εθνική Φρουρά) purchased 250 pistols for their special forces group.

[11] The IOM model incorporated several modifications to the weapon's design, such as the addition of an M1913 accessory rail, a magazine safety mechanism, and fully adjustable sights.

[31] The USG model incorporates a conventionally shaped square trigger guard, a reversible magazine release, and other minor changes.

[8] The grip texture on current pistols is extensively checkered for a superior hold, and each side of the slide has a series of narrow ridges at the rear to aid grasping.

[33] One of the design intents for the standard 5.7×28mm cartridge type, the SS190, was that it would have the ability to penetrate Kevlar protective vests—such as the NATO CRISAT vest—that will stop conventional pistol bullets.

[39] With an additional cartridge in the chamber, the Five-seven pistol has a total capacity of 11, 21, or 31 rounds depending on which magazine type is used.

[8][11] A chamber indicator, in the form of a pin inside a tiny hole, is provided on the left side of the slide.

[8] The pistol's push-button magazine release, located on the left side of the frame where the trigger guard intersects with the grip, is square-shaped and reversible for left-handed shooters.

[8][11] The "three-dot" type adjustable sights consist of a 2.9-mm (0.12 in) square notch rear and a 3.6-mm (0.14 in) blade front, which has a height of 9.2 mm (0.36 in).

[8][44] With the use of an extended, threaded barrel, the pistol can also be fitted with various sound suppressors developed by Advanced Armament Corporation, Gemtech, Silencerco, and other manufacturers.

[22][45] Israeli manufacturer FAB Defense offers a complete PDW conversion kit for the Five-seven, designated the KPOS G2 FN 5.7, that allows the pistol to be reconfigured into a shoulder-fired personal defense weapon, and CornerShot offers a weapon system compatible with the Five-seven that allows the shooter to aim and fire around corners without being exposed.

[19][54] The National Rifle Association of America (NRA) shortly countered the Brady Campaign's claim by stating that the gun control group may not have adhered to standard testing procedures, and that FN offers armor-piercing varieties of the 5.7×28mm cartridge only to military and law enforcement customers.

[54][55] Varieties offered to civilians are classified by the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) as not armor-piercing, and it was stated that the SS192 and SS196 cartridge variations were unable to penetrate various types of Kevlar vests in tests conducted by FNH USA.

"[57] In the same year, two pieces of legislation were introduced in the United States Congress, specifically targeting the Five-seven pistol and 5.7×28mm ammunition for a federal ban: the H.R.

Various news sources such as The Boston Globe and La Jornada also report incidents in which the pistol was used to shoot and kill police officers or civilians in Mexico.

[66][67] In November 2009, the Five-seven again became subject to controversy in the United States, following the shooting at Fort Hood military base, in Texas.

[20][53][63] A U.S. Army psychiatrist, Major Nidal Hasan, opened fire on fellow soldiers with a Five-seven pistol, killing 13 people and wounding 29 in the worst shooting ever to take place on an American military base.

[20][53][63] Shortly after the shooting, FNH USA responded with a fact sheet dismissing allegations about the nature of the pistol, stating that it is only offered to civilians with sporting ammunition.

[40] Later in the month, a number of gun control organizations such as the Brady Campaign wrote a collaborative letter to U.S. President Barack Obama, citing the weapon's use by the Fort Hood shooter and Mexican drug cartels, and calling on him to ban importation of the Five-seven pistol and 5.7×28mm ammunition.

[69] The first military organization to adopt the Five-seven was the Cypriot National Guard (Greek: Εθνική Φρουρά), which purchased 250 pistols in May 2000 for its special forces group.

[citation needed] In the United States, the Five-seven (as of 2010) is used by over 300 law enforcement agencies, including the U.S. Secret Service.