The film begins with background that reads: "In May 2007, the men of Second Platoon, Battle Company began a 15-month deployment in the Korengal Valley of eastern Afghanistan. It was considered one of the most dangerous postings in the U.S. Military." The film chronicles the lives of the men from their deployment to the time of their return home, and begins with video footage of PFC Restrepo on a train one week prior. The goal of the deployment was to clear the Korengal Valley of insurgency and gain the trust of the local populace. The Korengal flows north to the Pech, which then flows east to the Kunar River valley on the porous border with Pakistan. As an example of the ever-present dangers, the first scenes cover a fire-fight after a military Hummer is disabled on a narrow mountain road by an IED. The soldiers are ferried in by Chinook and begin their deployment at Combat Outpost Korengal, or "KOP", and early in the campaign PFC Juan S. Restrepo is killed, as well as another team member, PFC Vimoto. The film portrays negotiations with the local people, construction of an advanced outpost called "OP Restrepo", as well as the challenges and intermittent fire-fights they face. In the latter part of the film, the dangerous mission Operation Rock Avalanche is shown along with some of its tragic consequences. One event was the lossto Battle Company of Army Sgt. Larry Rougle. It was there, in 2007, when Army Sgt. Rougle, who served two tours in Iraq and three in Afghanistan, was ambushed by a large number of Taliban. It was learned that Rougle, at point, took the brunt of the attack, allowing his soldiers to secure a position and fight. Army Sgt. Larry Rougle, who is a recipient of the Purple Heart, is buried in Arlington National Cemetery. Restrepo is a film not just about the events of combat, but also about "brotherhood," according to Junger. The film shows the dedication to their duty as a soldier and their commitment to one another as brothers. The film is narrated by several men who fought with PFC Juan S. Restrepo. The men discuss loss such as dead civilians and soldiers, as well as the emotional distress that the soldiers are left with in its aftermath. The film ends with a coda that reads: "In April 2010, the United States Army withdrew from the Korengal Valley. Nearly 50 American soldiers died fighting there."
In March 2014, Realscreen magazine revealed that Junger was working on a sequel to Restrepo, titled Korengal. The film was released in theaters in New York on May 30, 2014, with a pay-VOD release following in September 2014. The sequel "departs from the vérité style of the original somewhat, as it features an original score and some archival news footage".