In an ornate baroque hotel populated by wealthy individuals and couples who socialize with one another, a man approaches a woman and claims they met the previous year at a similar resort (possibly Frederiksbad, Karlstadt, Marienbad, or Baden-Salsa) and had an affair.

Conversations and events are repeated in different parts of the building and grounds, accompanied by numerous tracking shots of the hotel's corridors with ambiguous and repetitive voice-overs.

The film offers no definitive conclusion regarding what is real and what is imagined, but by the end, the woman relents and leaves the hotel with the first man.

Robbe-Grillet described its basis: Alain Resnais and I were able to collaborate only because we saw the film in the same way from the start; and not just in the same general outlines but exactly, in the construction of the least detail as in its total architecture.

[3]The screenplay Robbe-Grillet wrote was very detailed, specifying not only the dialogue and gestures and décor, but also the placement and movement of the camera and the sequencing of shots in the editing.

[12] Resnais showed his costume designer photographs from Marcel L'Herbier's L'Inhumaine (1924) and L'Argent (1928), for which great fashion designers of the 1920s had created the costumes, and asked members of his team to look at other silent films, particularly G. W. Pabst's Pandora's Box (1929), as he wanted Seyrig's appearance and manner to resemble that of Louise Brooks in that film.

[20][21] The controversy was fueled when Robbe-Grillet and Resnais appeared to give contradictory answers when asked whether the man and woman had actually met at Marienbad last year or not, as this was used as a means of attacking the film by those who disliked it.

The website's critics consensus reads: "Elegantly enigmatic and dreamlike, this work of essential cinema features exquisite cinematography and an exploration of narrative still revisited by filmmakers today.

[35] Numerous explanations of the film's events have been put forward, among them: that it is a version of the Orpheus and Eurydice myth, that it represents the relationship between patient and psychoanalyst, that it all takes place in the woman's mind,[36] that it all takes place in the man's mind and depicts his refusal to acknowledge he has killed the woman he loved,[37] and that the characters are ghosts or dead souls in limbo.

"[41] As a suggestion of how one might view the work, he offered, "The whole film, as a matter of fact, is the story of a persuasion: it deals with a reality which the hero creates out of his own vision, out of his own words.

"[43] The impact of Last Year at Marienbad upon other filmmakers has been widely recognized and variously illustrated, extending from French directors such as Agnès Varda, Marguerite Duras, and Jacques Rivette to international figures such as Ingmar Bergman and Federico Fellini.

Terence Young stated that he styled the pre-credits sequence of the James Bond film From Russia with Love (1963) after Marienbad.

[47] Peter Greenaway said the film had been the most important influence upon his own filmmaking (and he himself would go on to establish a close working relationship with its cinematographer, Sacha Vierny).

[57][58] Alain Resnais participated in this release, and he insisted it include an unrestored soundtrack in addition to the restored one, saying: Sound recording and reproduction techniques have changed a lot over the decades.

If one remasters a film so as to tailor it to the standards of 2009, there is a danger of altering drastically the balance of the voices, the sound effects, and the music.