The MP5K has considerably less recoil and side to side rocking than its Modern Warfare 2 counterpart. It is unlocked at level 1, as it is part of the SMG default class. The MP5K lacks rails, sling brackets, and a curved magazine that its Modern Warfare 2 counterpart sported. The rate of fire is also decreased.

The MP5K has one of the slowest reload times of any SMG. This can be remedied with Sleight of Hand, however with a magazine capacity of 30 (45 with Extended Mags), reloading isn't something users will have to do very often, and with the MP5K's high power, one can cleave through a group of enemies before needing to reload; this combo can turn the MP5K into a rather devastating room-clearing weapon. In addition, it also sports a tremendous hipfire accuracy, making Steady Aim quite useful. Considering this weapon is designed for CQB, burst fire at a range to stay on target. Due to its high power, fairly low recoil, and being fully automatic, it is extremely useful as an early-level weapon. Also this weapon has a great hip fire use which combined with it's firepower can be a useful close range gun.

The MP5K is also quite effective with the Rapid Fire attachment, as the increase in fire rate helps take out short range targets at a much quicker rate, but the player will have to take into account the massive increase of recoil at medium-long distances. Scavenger is recommended while using Rapid Fire, as Rapid Fire will burn through the player's ammunition.

The MP5K was confirmed in an E3 video from MSNBC here along with the MP5 to be in the upcoming Modern Warfare 3.