Colin Farrell won a Golden Globe Award for Best Actor in a Musical or Comedy for the film, while Martin McDonagh won a BAFTA Award for Best Original Screenplay.

Two hitmen hide out in the city of Bruges, and amidst the city's storybook background they come to terms with issues of guilt, morality, and redemption.

During his first job, rookie hitman Ray (Colin Farrell) accidentally kills a young boy. He and his senior colleague Ken (Brendan Gleeson) are sent to Bruges by their employer Harry Waters (Ralph Fiennes), and told to await further instructions. While Ken takes in the sights and historic medieval buildings, Ray is morose and withdrawn, wracked with guilt over being responsible for the death of a child (Theo Stevenson). One night, while observing a film shoot with the dwarf actor Jimmy (Jordan Prentice), Ray strikes up a romance with Chloë (Clémence Poésy), a local drug dealer and thief, moonlighting as a production assistant. On a date, Ray gets involved in a fistfight with a couple from Canada (Željko Ivanek and Stephanie Carey), mistaking them for Americans. Later that night, Chloë's former boyfriend Eirik (Jérémie Renier) threatens Ray with a handgun loaded with blanks, but Ray disarms him and shoots Eirik in the face, partially blinding him.

Despite his budding romance with Chloë, Ray's guilt at his accidental killing of the boy continues to haunt him. Ken finally receives a call from Harry, who orders him to kill Ray on the principle that the killing of a child — even accidentally — is unforgivable. He would expect the same penalty if it happened to him, as Harry is a family man himself. Ken retrieves a handgun from Harry's local Belgian contact and tracks Ray to a park. As Ken sneaks up behind Ray to kill him, he sees Ray is about to shoot himself. His concern for his young charge overrides his sense of duty to their employer, and Ken prevents Ray's suicide. Ken then confesses to Ray that he had been ordered by Harry to kill Ray, although Ken denies that he intended to go through with the execution. While the two discuss the situation, Ken disarms Ray and convinces him to leave the city and the business. Following Ray's departure, Ken calls Harry, reveals his insubordination and location, and abruptly hangs up. An enraged Harry immediately heads to Bruges, where he gets a gun from his contact.

Before Ray's train has travelled far from the city, he is arrested for assaulting the Canadian couple and escorted back to Bruges. Ken and Harry meet for a drink, before ascending the steps of Bruges' belfry. At the top of the carillon tower, Ken declares that Ray deserves a chance at redemption, but refuses to fight Harry in defense of his own life. Harry, while furious, takes pity on Ken and shoots him in the leg rather than kill him. Meanwhile, Chloë bails Ray out of jail, and the two share a drink on the market square beneath the belfry. When Eirik informs Harry of Ray's location, Ken fights with Harry for Ray's sake, and is shot in the neck. Harry descends the steps to confront Ray, leaving Ken. Seriously wounded, Ken drags himself back to the top of the carillon tower and searches for Harry in an attempt to shoot him before he harms Ray, but due to fog, he cannot see from the tower. Ken decides to jump off with his gun, hoping to allow Ray to use it in his defence. After first scattering coins to clear the area below of people, he jumps and lands in the plaza, living just long enough to warn Ray of Harry's arrival. However, the gun is shattered by the fall.

Ray flees back to the hotel for his gun, which Ken had stashed in a drawer in their room. Harry arrives soon after, but the pregnant owner (Thekla Reuten) of the hotel refuses to allow him up the stairs. Shouting through the stairwell, both men agree that Ray will try to flee from the back of the hotel, and Harry will run after him and shoot him if he can. Ray jumps on to a passing boat and loses his gun in the process. Ray looks back in time to see Harry drawing down on him from a bridge, but doubts that Harry will be able to make the shot due to the distance. Despite the long range, Harry fires and hits Ray in the abdomen. Harry pursues the now-wounded Ray through the streets before stumbling onto the film set, where Jimmy is in costume as a schoolboy. Harry shoots Ray another three times and in the process inadvertently shoots Jimmy in the head. Mistaking Jimmy's headless body for that of a child, Harry commits suicide on principle despite Ray's attempts to explain. The gravely-wounded Ray is lifted onto an ambulance as he sees the pregnant woman, Eirik and Chloë in turn. Once in the ambulance, Ray considers prison or death as sufficient recompense, but then wonders if hell consists of staying in Bruges forever, at which point he says he hopes to live. He then slips into unconsciousness, leaving his fate unclear.

The plot bears notable similarities to Harold Pinter's one-act play The Dumb Waiter. The film also contains many references to Don't Look Now, including the claim by Chloë that the film-within-a-film is an homage to that film.

At one point, Ken and Ray visit a museum and see Hieronymus Bosch' painting The Last Judgement. Actors in the "film-within-a-film" wear costumes resembling elements of the painting, creating a symbolism of Bruges as heaven, purgatory, and/or hell.

Ken is seen watching the beginning of Orson Welles' Touch of Evil, with its notable continuous take of a car bombing. This precedes a six-minute tracking shot of Ken speaking on the telephone with Harry, where Harry instructs Ken to assassinate Ray.

The film received generally favourable reviews from critics. As of September 2009[update], the review aggregator Rotten Tomatoes reported that 80% of critics gave the film positive reviews, based on 152 reviews. Metacritic reported that the film had an average score of 67 out of 100, based on 34 reviews. Chicago Sun-Times film critic Roger Ebert gave the film high praise and a four-out-of-four-star rating, saying, "This film debut by the theater writer and director Martin McDonagh is an endlessly surprising, very dark, human comedy, with a plot that cannot be foreseen but only relished."