It stars David Hemmings as a musician who investigates a series of murders performed by a mysterious figure wearing black leather gloves.

Twenty years later in Rome, Professor Giordani chairs a parapsychology conference featuring psychic medium Helga Ulmann.

English Jazz pianist Marcus Daly sees the murder from the window as he passes by and rushes to her apartment, finding her mutilated corpse.

Returning to Helga's apartment, Marcus has an epiphany: the supposed painting he saw on the night of the murder, and was subsequently unable to find, was really the killer's reflection in a mirror.

Carlo, scarred psychologically, compulsively drew the scene as a youth and as an adult tried to repress the memory of the homicide with alcohol: he attacked Marcus and Gianna to protect his murderous mother from their investigation.

Deep Red represented Argento's return to the horror genre after an attempted breakaway with the historical dramedy The Five Days (1974).

[9] Argento's original working title for the film was La Tigre dei Denti a Sciabola (The Sabre-Toothed Tiger), matching the "animal" motif of his previous gialli.

The close-up shots of the killer's hands, clad in black leather gloves, were performed by director Dario Argento himself.

[citation needed] The film's special effects, which include several mechanically operated heads and body parts, were created and executed by Carlo Rambaldi.

As was common in Italian filmmaking at the time, Deep Red was shot without sync sound, and all dialogue was dubbed in post-production.

The Italian dub cast included Isa Bellini (Calamai), Wanda Tettoni (Del Balzo), and Corrado Gaipa (Meniconi).

The English dub cast included Cyril Cusack, Ted Rusoff, Carolyn De Fonseca, Geoffrey Copleston, Michael Forest, and Edward Mannix.

The site's consensus reads: "The kinetic camerawork and brutal over-the-top gore that made Dario Argento famous is on full display, but the addition of a compelling, complex story makes Deep Red a masterpiece.

"[17] The review stated that the film "presents some striking visual compositions that raise it above the level of the usual subgenre offerings."

Club wrote, "Operating under the principle that a moving camera is always better than a static one – and not above throwing in a terrifying evil doll – Deep Red showcases the technical bravado and loopy shock tactics that made Argento famous.

"[18] AllMovie compared the film to other in Argento's work, noting that the film script was "significantly stronger and the actors much better"[19] AllMovie noted that "Each of the murders is perfectly choreographed with particular praise going to Glauco Mauri's killing" and that "The final reel wraps the film up in a thrilling manner and features two extremely graphic deaths that leave the viewer stunned as the credits roll"[19] Quentin Tarantino described being "rattled" by the movie as a teenager, and picked it as one of his favorite horror movies.

Upon consideration, examiners concluded that the 'fighting' dogs were actually playing, and a letter sent from the production company stated that the lizard on a knife was a 'visual effect'.

[citation needed] Their version restored the missing footage but kept the American end credit scene (a freeze-frame shot of Hemmings looking down into a pool of blood).

The 2-disc set was released uncut as part of the now out-of-print window slip cover sets which released a number of films by Argento and other directors; it contained several special features including interviews, a documentary, trailers, audio commentary, four cover artwork designs, an exclusive collector's booklet written by Alan Jones on the film, and a double-sided poster.

After failing to get Pink Floyd to replace Gaslini, Argento turned back to Italy and found Goblin, a local progressive rock band.

Argento signed them immediately, and they ended up composing most of the film's musical score[5] (three Gaslini compositions were retained in the final version).

The soundtrack was made available for the first time ever on vinyl after Waxwork Records released the complete score by Goblin on a triple LP.

[25] Two key sequences in this film influenced directors of later horror movies: the lead-up to the famous exploding head scene in David Cronenberg's Scanners is modeled after the parapsychology discussion at the beginning of Deep Red, and Rick Rosenthal's Halloween II contains a scalding water death inspired by the death of Giuliana Calandra's character Amanda Righetti here.

[12] Profondo Rosso, a Rome horror memorabilia store owned and operated by Argento and Luigi Cozzi, is named after the film.