The film opens in Mexico, with Colonel John "Hannibal" Smith held captive by two corrupt Mexican officers, working for the renegade General Tuco. Hannibal escapes after being left to be fed on by two guard dogs, and sets out to rescue his comrade-in-arms, the lothario Templeton "Faceman" Peck, who is himself held captive by Tuco at Tuco's private ranch, where Face had seduced the General's wife. Hannibal makes it to the ranch in time to save Face from a grisly demise, after enlisting disgraced Ranger Bosco "B.A." Baracus, driving to the rescue in B.A.'s souped-up GMC Vandura van. With the three men now on the run from the enraged Tuco, they stop in at a nearby Army hospital, to recruit the services of insane pilot H.M. "Howling Mad" Murdock. In a medical chopper, they engage Tuco in a vicious aerial dogfight, which results in B.A.'s permanent fear of flying, and ends when they manage to lure Tuco's chopper into American airspace, where it's destroyed by a U.S. F-22 Raptor - the capstone to an elaborate plan put together by Hannibal.
The film then moves forward "eight years and 80 successful missions later", where the A-Team - now a highly-regarded, elite combat unit - is stationed in Iraq. Hannibal is contacted by CIA Agent Lynch, who reveals that Iraqi insurgents are in possession of U.S. treasury plates being used to manufacture counterfeit currency. Lynch wants Hannibal and his team to steal the plates and over one billion dollars in counterfeit cash that's due to be moved out of Baghdad. At the same time, DCIS Captain Charissa Sosa arrives on the scene, warning her ex-lover Face, whom along with the rest of team she has disdain for, to stay away from the plates and out of Baghdad. Against the advice of his commanding officer, General Morrison, Hannibal agrees to steal the plates, albeit in an unofficial "Black Ops" mission. The mission is successful, but when the team returns to base to meet their commanding officer, both the shipping container carrying the money and Morrison's Humvee are destroyed by men from the private security firm Black Forest (a fictionalized version of Blackwater), led by the ruthless Brock Pike. With Morrison the only proof that they were, in fact, acting on the U.S.'s behalf, the team is arrested, tried, dishonorably discharged and sentenced to ten years in federal prison.
Six months later, a still-incarcerated Hannibal is visited by Lynch once more, who reveals that Pike may be trying to sell the plates on the black market with the help of a mysterious Arab backer. Hannibal, who has been tracking Pike on his own from his prison cell, strikes up a deal with Lynch: clean records for himself and his team, in return for the plates. Lynch agrees, and Hannibal escapes prison with the help of a drug-soaked cigar that Lynch smuggles in that makes him appear dead after having a heart attack. Hannibal then breaks out Face from another military prison (pretending to be a removal man and stealing the tanning bed Face is in). Next, Hannibal and Face break out B.A. (by ripping off the door of the prison bus transporting him to another prison). The group then breaks out Murdock out of the V.A. mental hospital in Germany where he has been committed (by distracting the hospital staff and inmates with a 3D movie by which the team crashes their van through the wall of the building so Murdock can get in and escape). The four of them then drive to a local U.S. military base so they can steal a plane to leave the country.
By now, Sosa, who holds a grudge against the team for disregarding her warnings to stay away from Baghdad and getting her demoted to Lieutenant, is hot on the team's trail, and under the belief that the team is working with Pike, she tries to head them off before they leave Germany in a military Lockheed C-130 Hercules aircraft. The plane is destroyed by two remote-piloted drone fighters, but the team manages to escape inside the body of a tank on parachutes, which they "fly" by shooting rounds off and stalling their momentum.
Back on the ground, the A-Team tracks Pike, in the company of the mystery Arab to an office building in Berlin, and launch an offensive in which they manage to reclaim the plates and kidnap the Arab at the same time. With the slight exception of Hannibal, the team is shocked to learn that the "Arab" is actually General Morrison in disguse, who worked with Lynch and Pike to steal the plates, but then teamed up with Pike to double-cross Lynch and fake his own death. When Lynch learns that the team has Morrison in their possession, he orders an air strike to eliminate them all in one fell swoop. The team barely manages to escape, and Morrison is killed.
Realizing that their backs are to a wall, Face hatches a plan. Hannibal arranges to meet Sosa (knowing her phone lines are tapped by Lynch) on board a cargo ship at a downtown L.A. dock, saying he'll hand over Morrison and the plates in exchange for his freedom. Face then calls her on a second, untapped phone he had previously given her. Lynch reenlists Pike, and sets up a trap for Hannibal and company at the docks. This has been anticipated by Face, who sets off an elaborate series of diversions to split Lynch's team up, and more importantly, get Lynch directly involved. The plan nearly goes awry when Pike fires a rocket at the ship, nearly destroying it, but he's eventually killed by B.A. Lynch tracks down Hannibal and a hooded "Morrison", and shoots "Morrison" in the head before engaging Hannibal in a vicious fistfight. Hannibal soon gets the upper hand until Lynch grabs a hold of his gun, however the container they are in is lifted- revealing Sosa and dozens of Federal agents with guns drawn. "Morrison" is revealed to be Murdock in a melted-Kevlar helmet.
Lynch is taken into custody by the CIA, but contrary to what they were expecting, the A-Team is once again arrested by the military, this time for escaping incarceration. Sosa promises to do all she can to set them free, before kissing Face goodbye as he is led into a prison van. In the van, the team laments their misfortune, but Hannibal seems optimistic, and defers to Face, who reveals a key in his mouth presumably obtained from Sosa's kiss. Face then utters Hannibal's catch-phrase: "I love it when a plan comes together".
The film ends with a recital of the opening narration from the original television series.