One theme is the benefit of a strong father figure on young black males. As Furious tells Tre: "Any fool with a dick can make a baby, but only a real man can raise his children". Of Tre, Ricky, and Doughboy, only Tre's father is present in his everyday life (Ricky and Doughboy, though brothers, have different fathers). He leads a very different life than his two friends because of his father's guidance. His decisions, especially not to partake in the revenge of Ricky's death, happen because of the morals instilled in him.
The film deals largely with the seemingly unstoppable violence that plagues urban life. It is set in South Central Los Angeles, where Tre's father owns a house. The neighborhood is a violent one; the sounds of shootings and patrolling helicopters are heard often and even something as common as a passing car can mean death. The police that patrol the neighborhood seem indifferent to the notion of preventing crime. Early in the film, Furious frightens off a would-be thief with the pistol he keeps in a shoebox under his bed. The police, arriving an hour after Furious' call, do not seem concerned about the effect of the crime on the people they are supposed to protect. Additionally, the African American officer possesses a combative personality and has a tense exchange with Furious about the proper execution of his job. (As a teenager, Tre is pulled over by the same policeman while fleeing gunfire on Crenshaw Boulevard and the officer threatens him with his pistol, an act of police misconduct. This officer was based on a black officer encountered by John Singleton while growing up in South Central Los Angeles.) The officer's remarks to Tre's father at the beginning of the film (the officer wishes Furious's shot would've killed the man) show a belief that law enforcement is lazy and corrupt.
Tre also grapples with the moral implications of teenage sexuality. As a young man, and due no doubt to peer pressure, it is important to lose one's virginity. Tre's girlfriend, Brandi, has strongly resisted Tre's demands to have sex with her, mostly due to her own beliefs as a Catholic. It is clear that Tre has no wish to follow the path of Ricky, who fathered a son with his own girlfriend. Additionally, Tre's father gives him a tough lecture on the responsibilities and perils of becoming sexually active after Tre tells him a fabricated story about his first instance of sexual intercourse. The conversation arose from an off-handed remark by Tre about his future children, which causes some anxiety in his father who does not want to become a grandfather in his mid-30s.
The main theme in the movie is to "increase the peace" and is shown at the closing credits, as well as being hinted in the beginning segment when the audience is presented with a "STOP" sign.
Other themes present but not covered as extensively include gentrification of poor neighborhoods, drug abuse, sexual promiscuity, equality in college admission, and cultural bias in standardized testing.