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