More than 50 per cent of the population of Brazil is under 21, including more than three million homeless children — children who wander the teeming slums of principal cities like Rio de Janeiro and Sao Paulo; children who are the prey of older criminals and each other because Brazilian laws prevent anyone under 18 from being prosecuted for criminal acts. Pixote is about them.

Among those swept up during the periodic "cleansing" of the Sao Paulo streets are Pixote (Fernando Ramos da Silva), a baby-faced youngster long ago abandoned by his parents, Lilica (Jorge Juliao), an effeminate teenager, and Diego (Jose Nilson dos Santos), another young outcast. Incarcerated routinely in a juvenile detention centre, the trio soon experiences everything from inmate rape to police brutality and murder. It is a brutalization as casual as it is complete.

Aided by Dito (Gilbert Moura), an older, almost desperately macho teenager who is Lilica's lover, the trio finally flee the school and embark on a life of petty crime. They advance from small thefts and purse snatchings until Dito makes contact with Cristal (Tony Tornado), a dealer who commissions the gang to make a cocaine delivery to Rio. They mess up the deal, but steal enough money to move a bit higher in their strata. They buy the "rights" to Sueli (Marilia Pera), an aging whore, from her current pimp, and set her up more as a decoy than as a hooker.