Set in Echo Park, Los Angeles, the film follows the lives of two young Mexican American cousins who become estranged from their families—Magdalena (played by Emily Rios) because of her unwed teenage pregnancy and Carlos (Jesse Garcia) because of his homosexuality—and are taken in by their elderly great-uncle Tomas (Chalo González).

The film was inspired by Glatzer and Westmoreland's experience as a white gay couple moving into the gentrifying neighborhood of Echo Park, a predominantly Hispanic working-class community.

Magdalena, a fourteen-year-old girl from a working-class Mexican American family in Echo Park, Los Angeles, attends her cousin Eileen's quinceañera, an extravagant coming-of-age ceremony to celebrate her fifteenth birthday.

Magdalena herself is about to turn fifteen but her parents cannot afford to host a quinceañera as lavish as Eileen's, and they deny her repeated requests to hire a Hummer limousine for the occasion.

[1] They conceived the idea for the film in January 2005, based on their own experiences as a white gay couple moving into the predominantly Latino working-class neighborhood of Echo Park, Los Angeles, as the area underwent gentrification.

[1] Quinceañera premiered on January 23, 2006, at the Sundance Film Festival,[4] where it won both the Grand Jury Prize and the Audience Award in the dramatic feature category.

The site's consensus reads, "This slice-of-life story of a teenage girl in Echo Park is both a sweet crowd-pleaser and a perceptive look at socioeconomic community issues.

[14] Variety critic David Rooney summarized Quinceañera as "a fresh, spirited drama, charming and unpretentious" as well as a "small gem of a movie with a stirring soul".

[15] Stephen Holden of The New York Times described the film as "smart and warmhearted" with "a wonderfully organic feel for the fluid interaction of cultures and generations" in Los Angeles.

[18] Wesley Morris, writing for The Boston Globe, found the film to be "a modest but remarkably poignant comedy" and believed that, despite the predictability of the broader story, "somehow it feels authentic in all its small details".

[19] The San Francisco Chronicle's Ruthe Stein commented that the film was "directed with obvious love" by Glatzer and Westmoreland and commended González for his "hypnotic performance" as Tomas.

[20] Gianni Truzzi, who reviewed the film for the Seattle Post-Intelligencer, wrote of its "charm, sensitivity and intelligence" as well as the "great authenticity" of Rios's portrayal of Magdalena.

[21] Conversely, Lisa Schwarzbaum of Entertainment Weekly, who gave the film a C grade, found the plot "contrived" and melodramatic, and summarized it as "suds being sold as ethno-sensitive reality".

[22] The Christian Science Monitor's Peter Rainer felt that the Quinceañera "is best approached with lowered expectations", and that despite being "heartfelt and well-observed" it failed to adequately explore its contrasting themes of race, sexuality and religion.