Full list of all 65 Left 4 Dead 2 achievements worth 1,500 gamerscore. It takes around 20-25 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 15 achievements worth 500 Gamerscore.
Kill a Charger with a melee weapon while they are charging.
As the Charger, bowl through the entire enemy team in a single charge.
Survive the Dead Center campaign.
Survive the Dark Carnival campaign.
Survive the Swamp Fever campaign.
Survive the Hard Rain campaign.
Survive the Parish campaign.
Decapitate 200 Infected with a melee weapon.
Use every melee weapon to kill Common Infected.
Kill 100 Common Infected with the chainsaw.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Deploy an ammo upgrade and have your team use it.
Ignite 50 Common Infected with incendiary ammo.
Kill 15 Infected with a single grenade launcher blast.
Use a bile bomb on a Tank.
Kill one of each Uncommon Infected.
Kill 10 swampy Mudmen while they are in the water.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Honk the noses of 10 Clowns.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Kill a Spitter before she is able to spit.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
Rescue Gnome Chompski from the Carnival.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
In a Survival round, get a medal only using melee weapons.
Win a game of Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
As the Charger, grab a Survivor and carry them over 80 feet.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Make a Survivor drop a gas can during overtime.
As the Jockey, ride a Survivor for more than 12 seconds.
Survive all campaigns on Expert.
Survive a campaign on Expert skill with Realism mode enabled.
Finish a campaign using only melee weapons.
Kill a Tank with melee weapons.
Revive 10 dead Survivors with the defibrillator.
Defend yourself at the crashed airliner without taking damage.
Navigate the sugar mill and reach the safe room without killing any Witches.
Cross the bridge finale in less than three minutes.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
As the Jockey, ride the Survivors twice in a single life.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Spitter, hit every Survivor with a single acid patch.
As the Spitter, spit on a Survivor being choked by a Smoker.
Collect 100 gas cans in Scavenge.
Collect 15 gas cans in a single Scavenge round.
Cause 25 gas can drops as a Special Infected.
Survive The Passing Campaign.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Using the M60, kill 25 infected without letting go of the trigger.
Collect 10 items dropped by a Fallen Survivor.
Play 6 Mutations.
Knock off the heads of 18 infected with the golf club.
Play the new Midnight Riders song on a jukebox.
Kill a Tank only with damage from the original Survivors.
Open 5 foot lockers.
Play 5 full games of Scavenge on The Port.
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
Complete "The Sacrifice".
Have Bill sacrifice himself for the team.
As a Special Infected, incap someone who is trying to sacrifice themselves.