Full list of all 65 Left 4 Dead achievements worth 1,500 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 15 achievements worth 500 Gamerscore.
Kill 53,595 Infected.
Dole out 5000 total Survivor damage as a Special Infected.
Kill 1000 Infected with a mounted machine gun.
Kill all four Survivors in one life while playing as a Tank.
As an Infected, incap a Survivor who has entered and left a safe room.
Drag a Survivor 100 feet with your tongue.
Cover four Survivors with Boomer bile at once.
Constrict two Survivors in one life as a Smoker.
Survive a campaign with no Survivors taking damage from Special Infected.
All Survivors complete a campaign without being vomited on.
Play an entire campaign with no Survivors taking friendly fire damage.
No Survivors take damage after contacting the rescue vehicle.
Survive all campaigns on Expert.
Survive any campaign on Expert.
Sneak past all Witches in a campaign without disturbing one.
Survive a campaign without being incapacitated.
Pounce two different Survivors in one life as a Hunter.
Give pain pills to 10 Survivors.
Heal 25 Survivors with a first aid kit.
Kill a Witch with a single headshot.
Punch a Hunter as he is pouncing.
Single-handedly kill a Tank.
Kill an Infected with a single blow from behind.
Finish a campaign without ever being healed.
Survive the Blood Harvest campaign.
Kill a Witch without any Survivor taking damage from her.
Survive an entire campaign using only pistols.
Revive 50 incapacitated Survivors.
Survive the No Mercy campaign.
Leave a safe room to save an incapped teammate and bring them back safely.
Set 101 Infected on fire.
Light a Witch with a Molotov.
Headshot a Hunter while he's leaping.
Save another Survivor from a Special Infected while on the ground.
Shove a Hunter off of a pinned and helpless Survivor.
Kill 10 Smokers as they are pulling helpless Survivors.
Shove a Boomer and then kill him without him splashing on anyone.
Light a Tank with a Molotov.
Protect any Survivor from an attacking Infected 50 times.
Heal a fellow Survivor when your own health is below 10.
Survive the Dead Air campaign.
Beat a campaign with all 4 Survivors.
You or another Survivor take no damage after being vomited on by a Boomer.
Make 100 headshot kills.
Survive the Death Toll campaign.
Rescue a Survivor trapped in a closet.
Kill a Tank without it dealing any damage to a Survivor.
Free yourself from a Smoker who has grabbed you with his tongue.
Rescue a Survivor from a Smoker's tongue before he takes damage.
Blow up 20 Infected in a single explosion.
Kill 5,359 Infected in the Crash Course campaign.
Smoker pull a bile-covered Survivor until you hold him during Crash Course.
Pounce a Survivor for 25 points of damage in the Crash Course campaign.
Your team incapacitates three Survivors within five seconds in the Crash Course campaign.
Stun a Tank with an explosion in the Crash Course campaign.
Your team wipes all Survivors after the escape vehicle has opened in Crash Course.
Win a Versus campaign of Crash Course.
Restart the generator within 30 seconds of it shutting off in the Crash Course campaign.
Survive the Crash Course Campaign.
As a Tank hit 20 Survivors with a car in the Crash Course campaign.
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.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".