Charles Starkweather had been executed by the time the film started production, but Caril Fugate was still alive and facing parole. The filmmakers changed the principal characters' names to avoid a lawsuit.
The actor originally cast as the architect that rings at the rich man's door did not show up, so Terrence Malick played the part himself. Malick later wanted to re-shoot the scene with another actor, but Martin Sheen refused to re-do the sequence with another person.
The film's tag line ("In 1959 a lot of people were killing time. Kit and Holly were killing people") inspired the Zodiac Killer, who had been lying low for years, to write a letter to a newspaper denouncing their flippant attitude to violence in society by running such an ad.
The article "Absence of Malick" written by David Handelman and published in California Magazine stated that Terrence Malick filmed this picture " . . . in Eastern Colorado between August and October of 1972. He, reportedly, gave investors no guarantee of completion or distribution, paid himself no salary and his actors and crew not much more. The costumer, mechanic and Malick himself all ended up acting in the film. As not only director, but producer, Malick suddenly found himself dealing with insurance costs, auto maintenance, unionizers, shotgun-wielding landowners and a mutinous crew. His first cinematographer, Brian Probyn, wouldn't shoot what Malick wanted, claiming the scenes wouldn't cut together. Probyn's assistant, Tak Fujimoto, then took over, but also left. Some equipment was damaged by the film's fire sequence. When a special-effects man suffered severe burns, Malick, unable to afford a helicopter, sent him to the distant hospital by car, and many crew members quit in protest. For the last two weeks of the shoot, the entire crew consisted of the director, the director's wife and a local high school student. Then Malick ran out of money whilst editing and had to take a rewrite job to finish his movie. When shown to the New York Film Festival selection board months later, the print broke, the sound was muddy, the picture was out of focus. Yet Badlands (1973) landed the prestigious closing-night slot and drew raves. Warner's paid $950,000 for the distribution rights".
Some movie posters for the film featured a long text preamble that read: "He was 25 years old - He combed his hair like James Dean - He was very fastidious - People who littered bothered him - She was 15 - She took music lessons and could twirl a baton - She wasn't very popular at school - For awhile they lived together in a tree house. In 1959, she watched while he killed a lot of people".
Writer-producer-director Terrence Malick has said of raising the finance for this picture: "I developed a kind of sales kit with slides and videotapes of actors, all with a view to presenting investors with something that would look ready to shoot. To my surprise, they didn't pay too much attention to it. They invested on faith".
The Carl Orff composed theme song ("Gassenhauer," sometimes called the "Street Song," from Orff's Musica Poetica) was later adapted by composer Hans Zimmer for the 1995 Tony Scott film "True Romance" (written by Quentin Tarantino). The later film has many other similarities and allusions to "Badlands."
The Turner Classics Movies article on this film written by Jeff Stafford states: "Badlands (1973) was [Terrence] Malick's feature film debut. Although he had previously worked as a screenwriter (Pocket Money (1972)), he decided to direct his own scripts after Paramount made a complete mess of his Deadhead Miles (1973) screenplay, transforming it into a film so bad it couldn't even be released. With his brother, Chris, Malick managed to raise $300,000 for Badlands (1973)'s pre-production costs. The additional money was raised by independent producer Edward R. Pressman from personal friends like former Xerox chief Max Palevsky".
Sissy Spacek later said that working with Terrence Malick completely changed her whole attitude to film-making. She reckons she would have had a much different career if she and Malick hadn't crossed paths.
Jack Fisk, the film's Art Director, said of this movie in 1982: "Whatever you see in Badlands (1973) is Terry's [Terrence Malick's] style, not mine. He's very strong visually. He was always willing, eager to change to things. He'd see something in the yard and say, 'Let's put that in the bedroom'. That's one thing I learned from him: spontaneity."
The movie's Badlands (1973) title is actually really a geographical term, but has a double meaning for the movie because of the murders that are committed. The Wikipedia website defines the badlands geography meaning as "a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. They are characterized by steep slopes, minimal vegetation, lack of a substantial regolith, and high drainage density. They can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, buttes, mesas, hoodoos and other such geological forms are common in badlands. They are often difficult to navigate by foot. Badlands often have a spectacular color display that alternates from dark black/blue coal stria to bright clays to red scoria".
About half of the financing for the movie was raised by writer-producer-director Terrence Malick and about half by the film's executive producer Edward R. Pressman. Reportedly, Malick contributed and put forward US 25,000 of his own money towards the picture.