The fourth season of It's Always Sunny in Philadelphia, premiered on FX on September 18, 2008. The season contains 13 episodes and concluded airing on November 20, 2008.

Season 4 Episode 1 - Mac and Dennis: Manhunters

Charlie and Dee have been stealing Frank's delicious meats, so Frank leaves out human meat to get back at them. Driven by their cannibalistic needs, Charlie and Dee go in search of human flesh. Mac and Dennis harass Frank for hunting defenseless animals and think it would be much more badass to hunt something that could fight back ... like a human. Air Date : 18th-Sep-2008  Read More

Season 4 Episode 2 - The Gang Solves the Gas Crisis

Charlie, Mac, and Dennis formulate a plan to take advantage of the rising gas prices. By purchasing excess amounts now, they can sell it in the future and profit. As usual, things don't go as planned. Dee is also out to make money when she learns that Bruce is going to give the family fortune to a Muslim cultural center. She and Frank try to stop him and get the cash for themselves. Air Date : 18th-Sep-2008  Read More

Season 4 Episode 3 - America’s Next Top Paddy’s Billboard Model Contest

Due to the gang's latest "business expenses," Paddy's is in dire need of money. Frank buys a billboard to advertise the bar, but Dee decides to create a viral video to post on YouTube for promotion. Charlie quickly joins her, leaving Frank and Mac to hold a contest for some hot models to feature on the billboard. Naturally, Dennis joins the competition to prove his worth. Air Date : 25th-Sep-2008  Read More

Season 4 Episode 4 - Mac’s Banging the Waitress

Charlie finds out that the waitress has been seeing someone. He calls on Mac, his so-called best friend, to find out more information about the guy and to beat him up. However, it turns out that Mac is the guy the waitress has supposedly been seeing. Dennis, heartbroken that he's not Charlie's best friend, tries to win him over. Air Date : 25th-Sep-2008  Read More

Season 4 Episode 5 - Mac and Charlie Die (1)

Part 1 of 2. Mac and Charlie fake their deaths to avoid the wrath of Mac's father who was released from prison and is out for vengeance. Air Date : 2nd-Oct-2008  Read More

Season 4 Episode 6 - Mac and Charlie Die (2)

Part 2 of 2. Dennis, Frank, and Dee find unique ways of coping with the apparent loss of their friends. Air Date : 2nd-Oct-2008  Read More

Season 4 Episode 7 - Who Pooped the Bed?

Charlie and Frank awake to find poop in their bed. Neither will confess to being the owner, so they, Mac, and Dennis try to scientifically deduce who dropped the deuce. Dee wants to do something a bit more sophisticated, so she invites the waitress and Artemis to a girls' night out. Air Date : 9th-Oct-2008  Read More

Season 4 Episode 8 - Paddy’s Pub: The Worst Bar in Philadelphia

A newspaper critic is kidnapped by the gang after he calls Paddy's pub the worst bar in Philadelphia. Air Date : 16th-Oct-2008  Read More

Season 4 Episode 9 - Dennis Reynolds: An Erotic Life

After discovering Dennis' erotic memoir, Mac and Frank attempt to make some money off of it. Meanwhile, Dee and Charlie decide to spend a day in each other's shoes. Air Date : 23rd-Oct-2008  Read More

Season 4 Episode 10 - Sweet Dee Has a Heart Attack

After Dee suffers a heart attack, she and Dennis try to live a healthier lifestyle. Meanwhile, Charlie and Mac take corporate jobs to get health insurance. Air Date : 30th-Oct-2008  Read More

Season 4 Episode 11 - The Gang Cracks the Liberty Bell

The gang fudge history by claiming that Paddy's Pub was responsible for cracking the Liberty Bell in an attempt to turn their dive into a Philadelphia landmark. Air Date : 6th-Nov-2008  Read More

Season 4 Episode 12 - The Gang Gets Extreme: Home Makeover Edition

Hoping to make their own dreams come true, the gang sets out to give an unexpected family an extreme home makeover. Air Date : 13th-Nov-2008  Read More

Season 4 Episode 13 - The Nightman Cometh

In the season finale, Charlie gets the gang to help him put together a rock opera based on his song "Nightman." Air Date : 20th-Nov-2008  Read More