A opening text informs the viewers that punk rock music did not start at CBGB, but in a basement in Connecticut. The story is mostly true. John Holmstrom and Legs McNeil are in their basement talking about starting Punk Magazine.
Hightstown, NJ, 40 years earlier. A baby escapes from his crib and runs away. His parents find him three miles away. Hilly Krystal (Alan Rickman) stands before a judge. He is divorced with two children and bankrupt again after a second failed attempt to open a nightclub. He walks around New York City with his dog and wanders into a small bar after picking up a junkie named Idaho. He asks the bartender if they ever play music there and decides he wants to buy the bar.
Hilly goes with Merv Fergueson, his former partner, to his mother to ask for money to buy the bar, which he does. He calls it Hillys on the Bowery. His teenage daughter Lisa (Ashley Greene) shows up to tell him that she cant afford school anymore and is dropping out. She crashes there while Hilly and Merv work on the bar, building a stage. He wants it to be for country, bluegrass, and blues music. Merv, upset, leaves with Idaho.
The name of the bar has now been changed to CBGB. Terry Ork (Johnny Galecki) shows up with his band, wanting to play there. He is the manager of the band Television. He convinces Hilly to let them play there, but only original music, even though they are a raw band. Hilly goes to find a man named Taxi, a man who knows mechanics, to hire him to be a sound engineer. Television starts to play, but Hillys main concern is that they don't play too loud.
Hilly goes with his dog to the homeless alley. There's a dead man outside. Stan the cop arrests Idaho, but leaves the body. He goes back to the bar and pays some bikers to get Idaho out of jail. Meanwhile, back at the bar, the band starts to play, but Merv is passed out in the shower upstairs blocking the drain which almost causes an electrical accident. Meanwhile, his mother wants her money back, so they start delivering pianos to raise some, breaking a piano in the process.
Thanks to Television, the club starts to gain publicity and his daughter Lisa wants to work there. Suddenly the bar is full and the punk magazine founders are hanging out there, hiring a girl named Mary. The band Talking Heads starts to play there, and Hilly invites the cop to see them play. Suddenly Blondie, Patti Smith, Iggy Pop, and a million other bands are playing there. Punk Magazine releases their first issue.
The Ramones show up, and they actually aren't very good. Despite the popularity of the club though they dont seem to be making any money because Hilly lets a lot of people in without paying cover charges and gives away a lot of free drinks.
The Dead Boys perform there and become very popular. Genya Ravan (Stana Katic) the record producer and other girls start to go wild, and the place is getting insane. Stan shows up to tell Hilly that they've been getting complaints about the type of people the club attracts. He's also three months behind on his rent. He starts to kick out junkies but the club becomes huge and no one is afraid of having sex or getting high in the bathrooms.
The Ramones sign a record deal and suddenly they are everywhere, except CBGB's. Men come to collect the rent, but Hilly had been making deals with the bikers, so they come and beat them up and take them away. Lisa flips out because she doesn't realize that Hilly hadn't been paying the rent and insists on taking over the books.
Hilly goes into the bathroom and leaves the water running while he falls asleep, completely flooding the upstairs, showing his irresponsibility. The bands keep coming, and Punk magazine is interviewing them and writing about sex, violence, and everything. Hilly starts managing the Dead Boys and wants Genya to produce them. While they perform one night, Hilly's mother shows up. Lisa forces Hilly into the office to talk with him and Merv about their finances. He doesn't care though. All he wants at the moment is to talk to Genya about producing the Dead Boys. Lisa goes to smoke a cigarette in the bathroom when she is visited by Idaho who doesn't mind peeing right in front of her. Hilly insists that The Dead Boys are going to be big.
Genya goes to talk to Hilly. She doesn't want to produce them, but agrees to anyway. Hilly pulls out tons of money that he has been hoarding away to get them started. She goes ballistic on the band because they have stickers of swastikas on their amp. They're pretty stupid and don't even know what they mean. They go on tour but are a hot mess and crash their bus. Hilly goes to the bank and finds out he only has $300 left in his bank account. He takes it out of the CBGB account and gives it to Genya. Meanwhile, the band gets into a fight, and one of the members, Blitz, almost dies in a knife fight. Hilly tells Genya to make sure Blitz gets the money for his medical expenses and he leaves the Dead Boys to go back to his hometown to his old house. On the phone, Lisa yells at him to get back there because of all the people who are depending on him. Even though he insists hes done, he returns. Lisa tells him shes going to law school, and they all raised money to help pay to keep the club open. Just then, The Police audition. He says There is definitely something there
We then see "Hilly gave a stage to some 50,000 bands during CBGB's 33 year tenure."
The movie ends with Hilly being interviewed by Punk Magazine. He says he opened CBGB because he thought country music would be the next big thing (and it was) in Nashville.