While negatively received upon its release, Up in Smoke grossed over $104 million, is credited with establishing the stoner film genre, and is now considered a cult classic.

They end up unknowingly involved in a plot to smuggle a van constructed completely out of "fiberweed" (hardened THC resin derived from marijuana - a play on the word fiberglass) from Mexico to Los Angeles, with an inept police narcotics unit led by the insane and anti-drug Sergeant Stedenko hot on their trail.

After narrowly avoiding arrest by a motorcycle cop who had gotten high off fumes from the “fiberweed” van, they arrive at the venue to find that most of the bands performing are being negatively received by the audience, which causes Man to freak out.

The duo's band, Alice Bowie, win over the audience, including the cops, who get stoned due to a large amount of marijuana smoke from the burning van being funneled into the venue.

[3] On April 10, 2018, a 40th Anniversary Edition set was released, which featured the movie on Blu-ray and DVD, and the album on vinyl record and compact disc, as well as a 7-inch picture disc vinyl record single featuring the songs "Earache My Eye" and "Lost Due To Incompetence (Theme From A Big Green Van)", with an image of Cheech from the film on the A-side and the "YESCA" license plate image on the B-side.

[12] The set also featured oversized Up In Smoke branded rolling papers, an 11×17 film poster and a booklet with new essays by both Marin and Chong, along with rare and unseen photos.

The site's consensus reads, "Oft-quoted but undeniably flawed, Up In Smoke is a seminal piece of stoner cinema thanks to the likability of its two counterculture icons.

[18] Vincent Canby of The New York Times called the film "a genially slapdash, sometimes winning live-action cartoon" with "several genuinely funny moments.

"[20] Gene Siskel of the Chicago Tribune gave the film half of one star out of four, calling it "one of the most juvenile, poorly written, awkwardly directed pictures I have ever seen.

[22] Kevin Thomas of the Los Angeles Times wrote that Cheech & Chong were "a likable, funky duo, but the script they've come up with for their film debut is severely underwritten."

"[23][better source needed] Pauline Kael of The New Yorker compared the film favorably to The Groove Tube, writing that Up in Smoke was "also crudely done but is more consistently funny."

Like, you know, the film suffers from a bad case of burn-out, leading one to nod off between jokes and wonder why producer Lou Adler bothered to attempt a Doper's Delight in this post-Woodstock age of Clean Living.

Written by Cheech Marin, Tommy Chong, and Eliot Rahal, the graphic novel acts as a sequel to the Up in Smoke film, as it features Pedro de Pacas and Anthony "Man" Stoner as the main characters of the story.