Buñuel's first film, it was initially released in a limited capacity at Studio des Ursulines in Paris, but became popular and ran for eight months.

With disjointed chronology, jumping from the initial "once upon a time" to "eight years later" without events or characters changing, it uses dream logic in narrative flow that can be described in terms of the then-popular Freudian free association, presenting a series of tenuously related scenes.

[Note 1][2] "Eight years later", a young man bicycles down an urban street wearing a nun's habit and carrying a striped box with a strap around his neck.

An androgynous young woman pokes at a severed human hand in the street below the apartment while surrounded by a large crowd.

The crowd clears when a policeman places the hand in the box previously carried by the young man and gives it to the androgynous woman.

The second man, now in a meadow, dies while swiping at the back of a nude female figure which suddenly disappears into thin air.

He shows her the time on his watch and they walk near the rocks, where they find the remnants of the first young man's nun's clothing and the box.

[3] The title of the film alludes to a Spanish idiom: "the Andalusian dog howls –someone has died!”[citation needed] The screenplay was written in a few days.

But when the proposal of one liked the other, it seemed to us magnificent, indisputable and immediately introduced into the script.”[4] In deliberate contrast to the approach taken by Jean Epstein and his peers, which was to never leave anything in their work to chance, with every aesthetic decision having a rational explanation and fitting clearly into the whole,[5] Buñuel made clear throughout his writings that, between Dalí and himself, the only rule for the writing of the script was: "No idea or image that might lend itself to a rational explanation of any kind would be accepted.

The film was totally in keeping with the basic principle of the school, which defined Surrealism as 'Psychic Automatism', unconscious, capable of returning to the mind its true functions, beyond any form of control by reason, morality or aesthetics.

"[8] The film was financed by Buñuel's mother, and shot in Le Havre and at the Billancourt Studios in Paris over a period of ten days in March 1928.

[15] In Buñuel's original script, the final shot was to feature the corpses of the man and woman "consumed by swarms of flies".

[17] The rotting donkeys are a reference to the popular children's novel Platero y yo by Juan Ramón Jiménez, which Buñuel and Dalí both hated.

Notable attendees of the première included Pablo Picasso, Le Corbusier, Jean Cocteau, Christian Bérard and Georges Auric, in addition to the entirety of André Breton's Surrealist group.

[22] Buñuel intended to shock and insult the intellectual bourgeoisie of his youth, later saying: "Historically, this film represents a violent reaction against what at that time was called 'avantgarde cine,' which was directed exclusively to the artistic sensibility and to the reason of the spectator.

"[23] Against his hopes and expectations, the film was a huge success amongst the French elite,[24] leading Buñuel to remark: "What can I do about the people who adore all that is new, even when it goes against their deepest convictions, or about the insincere, corrupt press, and the inane herd that saw beauty or poetry in something which was basically no more than a desperate impassioned call for murder?

Through their accomplishment with Un Chien Andalou, Dalí and Buñuel became the first filmmakers to be officially welcomed into the ranks of the Surrealists by the movement's leader André Breton, an event recalled by film historian Georges Sadoul: "Breton had convoked the creators to our usual venue [the Café Radio] ... one summer's evening.

"[27] Among the most enthusiastic viewers of the film were the wealthy couple Viscount Charles and Marie-Laure de Noailles, who commissioned Dalí and Buñuel to create a sequel, of around the same length, with sound, to be called La Bête Andalouse, in order to affirm its connection with Un Chien.

[28] Dalí stated that the theme of the new film was to parallel that of the first: "to present the straight and pure 'conduct' of someone who continues to pursue love despite wretched humanitarian ideals, patriotism and the other poor mechanisms of reality.

[31] Film scholar Ken Dancyger has argued that Un Chien Andalou might be the genesis of the filmmaking style present in the modern music video.