It follows Paul Groves (Peter Fonda), a director of television commercials in the process of divorcing his wife Sally (Susan Strasberg). In the hopes of finding meaning, he takes 250 micrograms of LSD, with the help of dealer Max (Dennis Hopper) and trip sitter John (Bruce Dern).
The Trip contains examples of:
- And Starring: "Starring Peter Fonda."
- Black Cloak: Paul alternately pursues and is pursued by two Ringwraith-esque beings in black hooded cloaks riding dark horses. At the end of his trip, they corner him on a beach and pull back their hoods, revealing themselves as Sally and Glenn.
- Character Tics: Before his trip starts, Paul rubs his fingers together and at one point walks his hand along a railing.
- Crucified Hero Shot: Done a number of times. In one shot, he has an actual cross behind him.
- Cutting Back to Reality: The film cuts back and forth between Paul's hallucinations and his real life; for example, as he drinks from a dish of stew held by the dwarf in a forest, there's a quick cut to him sipping from a glass of wine in John's apartment.
- Fanservice: There's a topless dancer in the nightclub Paul wanders into, as well as PG-13-rated nudity from Sally and Glenn (Salli Sachse), a hippie girl Paul becomes infatuated with, and a scene of Paul naked from behind.
- Freeze-Frame Ending: Thanks to Executive Meddling, the movie ends with a freeze-frame of Paul's face shattering to symbolize his broken and traumatized mind, although there's nothing else in the closing scene to suggest that his LSD experience hurt him.
- Fun with Acronyms: The film's tagline is "A Lovely Sort of Death."
- Lens Flare: During one of the shots of Paul running around in the desert.
- Literal-Minded: One of the effects of the LSD.Waitress: What can I get for you?
Waitress: No, not you, that guy over there.
Waitress: Okay, wise guy, what do you want to drink?
- Little People Are Surreal: A dwarf appears in the forest scene, helping his much larger friend prepare a stew. Later, he reappears on the carousel, where he yells, "Bay of Pigs!"
- Opening Scroll: The movie opens with a "Foreword" calling it a "shocking commentary on a prevalent concern of our time" and warning that the illegal manufacture and consumption of LSD can have fatal consequences.
- Single Malt Vision: Many of Paul's hallucinations feature quadruple, quintuple, or sextuple vision.
- Sleep Mask: John has Paul wear one for a few minutes at the very beginning of his trip.
- Spiritual Predecessor: Jack Nicholson worked on Head after The Trip, and there are definite similarities, to the point where Head plays almost like a parody of The Trip at times.
- Tears of Blood: One scene has Paul with red tears pouring down his face, holding what looks like a child's dismembered arm, while Sally stands across from him with blood dabbed on her face.
- Toplessness from the Back: Used in the sex scenes with Sally and Glenn.
- Troubled Fetal Position: When Paul's trip turns bad, he curls up on John's couch, saying, "Oh, I'm dead. I'll never get back. My body's gone."