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