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