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.
Heal 25 Survivors with a first aid kit.
Survive an entire campaign using only pistols.
Kill 10 Smokers as they are pulling helpless Survivors.
Headshot a Hunter while he's leaping.
Kill 53,595 Infected.
Survive all campaigns on Expert.
No Survivors take damage after contacting the rescue vehicle.
Survive a campaign with no Survivors taking damage from Special Infected.
Play an entire campaign with no Survivors taking friendly fire damage.
All Survivors complete a campaign without being vomited on.
Kill 1000 Infected with a mounted machine gun.
Dole out 5000 total Survivor damage as a Special Infected.
Kill all four Survivors in one life while playing as a Tank.
Drag a Survivor 100 feet with your tongue.
As an Infected, incap a Survivor who has entered and left a safe room.
Cover four Survivors with Boomer bile at once.
Revive 50 incapacitated Survivors.
Survive any campaign on Expert.
Sneak past all Witches in a campaign without disturbing one.
Single-handedly kill a Tank.
You or another Survivor take no damage after being vomited on by a Boomer.
Finish a campaign without ever being healed.
Light a Tank with a Molotov.
Survive a campaign without being incapacitated.
Pounce two different Survivors in one life as a Hunter.
Constrict two Survivors in one life as a Smoker.
Save another Survivor from a Special Infected while on the ground.
Light a Witch with a Molotov.
Give pain pills to 10 Survivors.
Punch a Hunter as he is pouncing.
Survive the Dead Air campaign.
Set 101 Infected on fire.
Survive the Death Toll campaign.
Beat a campaign with all 4 Survivors.
Blow up 20 Infected in a single explosion.
Protect any Survivor from an attacking Infected 50 times.
Make 100 headshot kills.
Shove a Boomer and then kill him without him splashing on anyone.
Survive the Blood Harvest campaign.
Kill a Tank without it dealing any damage to a Survivor.
Rescue a Survivor from a Smoker's tongue before he takes damage.
Kill an Infected with a single blow from behind.
Leave a safe room to save an incapped teammate and bring them back safely.
Rescue a Survivor trapped in a closet.
Heal a fellow Survivor when your own health is below 10.
Survive the No Mercy campaign.
Kill a Witch with a single headshot.
Kill a Witch without any Survivor taking damage from her.
Free yourself from a Smoker who has grabbed you with his tongue.
Shove a Hunter off of a pinned and helpless Survivor.
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 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.
Stun a Tank with an explosion in the Crash Course campaign.
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.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".
Have all 3 generators running at once in "The Sacrifice" finale.
As a Special Infected, incap someone who is trying to sacrifice themselves.