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