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