During a formal dinner party at the lavish mansion of Señor Edmundo Nóbile and his wife, Lucia, the servants unaccountably leave their posts until only the major-domo is left. After dinner the guests adjourn to the music room, where one of the women, Blanca, plays a piano sonata. Later, when they might normally be expected to return home, the guests curiously remove their jackets, loosen their gowns, and settle down for the night on couches, chairs and the floor.
By morning it is apparent that, for some inexplicable reason, they are unable to leave. The guests consume what little drinks and food are left from the previous night's party. Days pass, and their plight intensifies; they become thirsty, hungry, quarrelsome, hostile, and hysterical – only Dr. Carlos Conde, applying logic and reason, manages to keep his cool and guide the guests through the ordeal. One of the guests, the elderly Sergio Russell, dies, and his body is placed in a large cupboard. Much later in the film, Béatriz and Eduardo, a young couple about to be married, lock themselves in a closet and commit suicide.
The guests eventually manage to break open a wall enough to access a water pipe. In the end, several sheep and a bear break loose from their bonds and find their way to the room; the guests take in the sheep and proceed to slaughter and roast them on fires made from floorboards and broken furniture. Dr. Conde reveals to Nóbile that one of his patients, Leonora, is dying from cancer and accepts a secret supply of morphine from the host to keep her pain under control. The supply of drugs is however stolen by Francis and Juana, a brother and sister. Ana, a Jew and a practitioner of Kabbalah, tries to free the guests by performing a mystical ceremony, which fails.
Eventually, Raúl suggests that Nóbile is responsible for their predicament and that he must be sacrificed. Only Dr. Conde and the noble Colonel Alvaro oppose the angry mob claiming Nóbile's blood. As Nóbile offers to take his own life, a young foreign guest, Leticia (nicknamed "La Valkiria") sees that they are all seated in the same positions as when their plight began. Upon her encouragement, the group starts reconstructing their conversation and movements from the night of the party and discover that they are then free to leave the room. Outside the manor, the guests are greeted by the local police and the servants, who had left the house on the night of the party and who had similarly found themselves unable to enter it.
To give thanks for their salvation, the guests attend a Te Deum at the cathedral. When the service is over, the churchgoers along with the clergy are also trapped. It is not entirely clear though, whether those that were trapped in the house before are now trapped again. They seem to have disappeared. The situation in the church is followed by a riot on the streets and the military step in to brutally clamp down, firing on the rioters. The last scene shows a flock of sheep entering the church in single file, accompanied by the sound of gunshots.
Though Buñuel never states what the symbolism represents, and leaves it for the viewer to come to their own understanding, one critic, Roger Ebert, wrote a lengthy dissertation of his interpretation of the film's symbolism, which includes the following paragraph: "The dinner guests represent the ruling class in Franco's Spain. Having set a banquet table for themselves by defeating the workers in the Spanish Civil War, they sit down for a feast, only to find it never ends. They're trapped in their own bourgeois cul-de-sac. Increasingly resentful at being shut off from the world outside, they grow mean and restless; their worst tendencies are revealed.""Silvia Pinal as Leticia "La Valkiria"
Enrique García Álvarez as Alberto Roc
Jacqueline Andere as Alicia de Roc
César del Campo as Col. Alvaro
Nadia Haro Oliva as Ana Maynar
Ofelia Montesco as Beatriz
Patricia de Morelos as Blanca
Augusto Benedico as Dr. Carlos Conde
Luis Beristáin as Cristian Ugalde
Enrique Rambal as Edmundo Nóbile
Xavier Massé as Eduardo
Xavier Loyá as Francisco Avila
Ofelia Guilmáin as Juana Avila
Claudio Brook as Julio, the majordomo
José Baviera as Leandro Gomez
Bertha Moss as Leonora
Lucy Gallardo as Lucía Nóbile
Tito Junco as Raúl
Patricia Morán as Rita Ugale
Antonio Bravo as Sergio Russell
Rosa Elena Durgel as Silvia
Ryan Schneider as Freckle Chico
This film received the International Federation of Film Critics (FIPRESCI) award of the international critics and the Screenwriters Guild at the 1962 Cannes Film Festival. At the 1963 Bodil Awards, the film won the Bodil Award for Best Non-European Film.