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