As in the first Underworld, Selene's (Kate Beckinsale's) primary weapons are a pair of Beretta 92FS pistols that have been converted to full-auto and given compensators to make them more controllable in auto-fire. Several close-ups of the guns reveal that they have the AL-GI-MEC compensators also used on the Berettas in Leon (The Professional), whereas the Berettas in the first film had a different style of compensator. This is because the first Underworld was filmed in Hungary and the full-auto Beretta pistols were supplied by Bapty & Co. (U.K.), whereas Underworld: Evolution was filmed in Canada and had Canadian armorers, so a different set of Berettas had to be used.
At one point in the film, a two-tone Beretta 92FS can be seen in Tanis' (Steven Mackintosh's) arsenal. This one has been fitted with a Beretta M93R-style forward hand grip and flash hider, but it is recognizable as a 92FS due to the slide-mounted safety.
Walther P99
Selene (Kate Beckinsale) also once again uses a pair of two-tone Walther P99s fitted with the Walther Laser Modules as her secondary sidearms. She acquires them from Tanis' (Steven Mackintosh's) arsenal when she goes to his castle. Although they are the same configuration as the guns used in the first Underworld, these are, as with the Berettas, a different set of pistols.
Selene also uses a standard black P99 when she fights Marcus at the pier where Corvinus' (Derek Jacobi's) ship is docked, after she takes it from the body of a dead Cleaner.
Heckler & Koch MP5K
At the beginning of the film, Selene is armed with a Heckler & Koch MP5K fitted with a tactical flashlight when she and Michael (Scott Speedman) visit the vampire safehouse and re-arm.
Heckler & Koch MP5A3
Kraven (Shane Brolly) and his men are all armed with Heckler & Koch MP5A3 submachine guns fitted with Surefire foreends and tactical flashlights when they stumble upon Marcus' (Tony Curran's) tomb and awaken him. Also, when Selene and Michael are in the vampire safehouse, several more MP5A3s with Surefire grips are visible in the armory. Selene takes one of these weapons in her equipment bag, but it never gets used.
Norinco Type 84S
The Hungarian police officers who chase Michael (Scott Speedman) through the woods are armed with Chinese Norinco Type 84 underfolder assault rifles, recognizable by their less curved magazines for 5.56x45mm ammunition.
Norinco Type 56-1
Due to continuity errors, the Hungarian police officers' AKs occasionally switch from the 5.56x45mm Norinco Type 84 underfolder to the similar Norinco Type 56-1, which is the same gun except chambered in 7.62x39mm. This is most obvious when Selene flips one officer over. Also, many Type 56 rifles are visible in the armory cabinet when Marcus (Tony Curran) visits the vampire safehouse.
Winchester Model 1912
Several of the Hungarian police officers also carry Winchester Model 1912 riot shotguns, one of which is used by Selene to incapacitate its user by clubbing him with it.
CZ 75
The Hungarian police use CZ 75 pistols as their sidearms.
Heckler & Koch G36K
Some of Corvinus' Cleaners carry Heckler & Koch G36K carbine assault rifles as their weapon of choice, including the squad leader. In the climax of the film, Selene grabs a dead Cleaner's G36K and uses it to mow down Lycans before it runs dry. Another G36K (fitted with a G36C carry handle and loaded with UV ammunition) is wielded by Tanis (Steven Mackintosh) when Selene and Michael go to his castle, and later appears in Selene's hands after she disarms him.
Also, in several flashbacks from the first Underworld, slain Lycans are seen using G36Ks, which was their preferred weapon in that film.
Heckler & Koch UMP
Some of the Cleaners use Heckler & Koch UMPs as their weapons, in keeping with the Cleaners' apparent preference for Heckler & Koch weaponry. Twice in the film, Selene is also seen wielding UMPs taken from dead Cleaners, first when she fights Marcus at the pier, and later when she fights William.
Heckler & Koch MP7A1
The Cleaners also use the Heckler & Koch MP7A1 personal defense weapon. Near the end of the film, after the Cleaners have all been turned into Lycans, Selen grabs one Cleaner's MP7 while it is still slung on his body and empties it into him at point-blank range.
Remington 870
In the climax of the film, Selene wields a pistol-grip Remington 870 with synthetic furniture and a tactical flashlight fixed to the end of the magazine tube, which she unloads into Marcus at point-blank range...to no avail. This weapon also appears in the hands of one of the Cleaners seen on video footage earlier in the film.
Daewoo K3 SPW
Towards the end of the film, when Selene and the Cleaners have set off to find Marcus, one of the Cleaners uses a Daewoo K3 SPW light machine gun. This is a K3 that has been mocked up to resemble an FN Minimi SPW ("Special Purpose Weapon"); guns just like this one have also been seen in Walking Tall, Stargate: Atlantis, Postal, etc.
IMI Desert Eagle Mark VII
Tanis' (Steven Mackintosh's) weapons cache includes a pair of Desert Eagle Mark VII pistols. Also, in a flashback to the first film, a Lycan is shown loading another Desert Eagle with UV ammunition.