The bayonet has a different length depending on the weapon and model, with the Mosin-Nagant's appearing to be the longest and Type 99 appearing to be the shortest. However, all bayonets allow the same melee distance in-game.
In the campaign the bayonet is most commonly found attached to Arisaka rifles dropped by Japanese Banzai Chargers, in which case the weapon is called the "Arisaka Bayonet", but it is also found attached to the M1 Garand in the mission Little Resistance, used by the Marine Raiders as well as the player. In Multiplayer, a bayonet stab will kill the enemy instantly just like the knife. In campaign, the enemy will get a sucking chest wound, and will stand while holding their wound in pain before dying. Bayonets are also mentioned in the mission Ring of Steel, by the Commisar in his speech at the beginning of the level. However, it is never actually seen used by the Red Army or Germans in the campaign.
Kills from the bayonet in multiplayer will count towards weapon challenges, with the exception of the M1A1 Carbine, M1 Garand and Kar98k, which go toward knife challenges.
The M1897 Trench Gun's bayonet has the ability to Gib enemies, a feature that no other bayonets have.
The bayonet is able to kill a dog at long ranges even before the dog is able to strike, but it misses quite often against them. A bayonet used rapidly is much slower than a knife attack rapidly, which means if the dog is missed with the first thrust, the player is left open to be attacked.
On the Wii version, the bayonet stab only occurs when the aim assist feature is on.
Bayonet stabs to the head count as headshots for the weapon it's attached to.
In single player, if the player goes prone and uses the bayonet, the player will swipe the bayonet as if no enemy is around, even if there is one right in front of the player. Enemies hit by this move will still bleed out of their chest as if they had been stabbed.