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