In the new movie “A Guide To Recognizing Your Saints,” the director Dito Montiel gets to go home again. The film — and memoir on which it is based — are an homage to the New York that he knew as an adolescent.

Mr. Montiel grew up in Astoria, Queens, roaming the streets with his friends and observing the weird jumble of 1980’s New York. They had free reign of the city at night, meeting its strange inhabitants, finding wayward locations to take over, girls to chase, and occasionally laws to break.

Though most of his friends weren’t so lucky, Mr. Montiel went on to earn a good amount of fame in that decade. He modeled for Calvin Klein and Versace, befriended Bruce Weber and Allen Ginsberg, and, with his hardcore band Gutterboy, signed the first $1 million contract for an underground group.

The band’s fortunes did not last long, and Mr. Montiel went on to document his travails in the rambling memoir “A Guide To Recognizing Your Saints” (Thunder Mouth’s Press). The book slid between a hagiography of his family and friends, a recounting of his flirtations with success, and his strange interactions with New York City and its most often overlooked residents.

The film jumps off from the premise of the memoir, but does not parallel its erratic story. Instead it tells the story of an adult Mr. Montiel, played by Robert Downey Jr., making a long overdue visit back home after achieving literary success, as he recounts his not so glorious days back in Astoria.

Shia LeBoeuf plays the young Dito, and though it is close to impossible to see how Mr. LeBoeuf’s trusting face could age into Mr. Downey’s furrowed countenance, he puts in a nuanced and moving performance. His tender demeanor and passive charm set Dito apart from his contemporaries and add an unbalanced center to the story.

Interestingly, it is not Mr. LeBoeuf that most resembles the real Dito, but the ex-model turned actor Channing Tatum, whose aesthetic best captures the chiseled tuff that turned so many heads in early 1980’s New York. Mr. Tatum plays Antonio, Dito’s hothead best friend, who attacks everyone he can during the day and goes home to beatings from his father at night.

Those two are joined in the neighborhood by their friends Giuseppe (Adam Scarimbolo) and Nerf (Peter Anthony Tambakis), and young Dito’s love interest Laurie, played by Melonie Diaz and later by Rosario Dawson, and her friends. New to the group is the poet Mike (Martin Compston) from Scotland, who begins to help Dito think about life beyond Queens.

But just as he starts to think bigger than the old neighborhood, the place reasserts its hold over him. Tensions between rival factions have reached a fever pitch, and for reasons unexplained, Dito becomes the target of his group’s nemesis, the Reaper. As the altercations get increasingly violent, Dito begins to fear for his life, and realizes that he can have no future in Queens.

But his father Monty, played with shirtsleeve charm by Chazz Palminteri, cannot comprehend his son’s dilemma or why he’d want to leave the neighborhood. Monty is an old boxer who haunts the family kitchen, tossing off sage wisdoms and tinkering on an old typewriter in the kitchen while his wife tries to keep the household together despite the world swirling by them outside. Monty calls himself “the King,” but his domain stops shortly outside the door to his apartment.

Even after a death threat is put on his son’s head, Monty has trouble comprehending Dito’s anxieties. And just as Monty can’t understand that his grasp on the world he knew is slipping, Mr. Montiel’s memoir and film pay deference to a New York that was on its way out.

Back then, children who grew up on the streets of New York could feel like they ruled the place even if they didn’t have any money. And though it may no longer exist, it’s easy to see the appeal of Mr. Montiel’s story. It is a testament to the continued relevance of his upbringing that Hollywood is so frequently drawn to him. With a tiny budget, Mr. Montiel has attracted a significant stable of well-known actors and financiers (Trudie Styler and Mr. Downey were early advocates) to sign on to this project. It is even more impressive that this first-time screenwriter and director was able to make his story so compelling on the screen.

There are plenty of hiccups and gaps in the storyline that he presents here. And though the reuniting of Monty and his son makes for an intense scene, it’s never sufficiently explained how or why their relationship deteriorated so completely. But Mr. Montiel has used what he knows, namely the streets of New York and its residents, to make a film that proves how painful even the most inevitable of changes can sometimes be.