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