The House of Bernarda Alba is a reflection of Lorca's intense theatrical sense, meaning that the play's focus is less its simple plot and more the atmosphere created around it.
The entire play is set in Bernarda's house, where she lives with her five daughters, her maid La Poncia, and several other servants. The Alba family lives in a small village in Andalusia, a region of Spain.
Act I opens on La Poncia and a servant, who are cleaning the house while the funeral of Bernarda's husband takes place in the nearby church. They complain about how Bernarda tyrannically demands the house be kept too clean even though she should pay more attention to her unwed daughters. The funeral bells announce the end of the ceremony, and 200 women enter the house along with Bernarda and the daughters. They discuss whether Pepe el Romano, a local young man whom they expect to propose to Bernarda's eldest daughter Angustias because of the girl's inheritance, was at the church. Turned off by the gossip, Bernarda ends the visit and the mourners leave.
Bernarda then tells her daughters they must go through an eight-year mourning period for her dead husband, father to all of them but Angustias. Adela, the youngest daughter, shows right away that she is a free spirit and will not be easily dampened by Bernarda's repression. There is much talk that sets up how Angustias hopes to entice a proposal from Pepe through her money, and how all of the girls are interested in men but how Bernarda prohibits any expression of those interests.
Adela meanwhile runs outside and plays with the chickens, which the other girls find strange. Bernarda finds Angustias has applied makeup, and a fight nearly ensues before Maria Josefa, Bernarda's senile mother who is kept locked up in the back, enters yelling about how she wants to get married and run away. Bernarda has her caught and locked back up.
Act II opens with the girls sewing, a sign of their mourning period. They discuss how Pepe has been over late talking with Angustias, but there is some belief that he might stay later than Angustias thinks. La Poncia tells them about how little they can expect of men and about her husband. They gossip about Magdalena, a daughter who has recently been sleepless, and Martirio, a hunchbacked daughter, implies that Adela has been carrying on an affair with Pepe.
The women leave at Bernarda's behest, except La Poncia and Adela, who have an intense argument over the latter's affair with Pepe. The women hear reapers, men who work the fields, passing by and singing, and all stop fighting to listen. Amelia, another daughter, and Martirio, gossip further about how late Pepe stays at night, after Angustias has gone to bed. Angustias brings news that someone has stolen her photo of Pepe that she keeps under her pillow, and a violent struggle begins that ends with the revelation that Martirio stole it.
Worried about her daughters, Bernarda laments her lack of diligence and La Poncia cruelly insinuates that there is wickedness under her roof. The women are merciless in their argument, even when La Poncia shares that her sons see Pepe there until far later than Angustias is awake. The argument grows until news comes of a local girl who, ashamed of having had a child out of wedlock, had murdered her baby and was now about to murdered herself in punishment. As Bernarda celebrates the vicious murder of a wicked woman, Adela protests it futilely, since this could well be her.
Act III opens a bit later, after the engagement between Angustias and Pepe has happened. All of the women are onstage with a visitor, Prudencia, who is sad over having had to banish her daughter for wickedness. They hear a stallion banging against its door out in the yard.
La Poncia and Bernarda have another fight, and then all the women go to bed. Later, Adela sneaks outside and Martirio starts to follow, but Maria Josefa enters, holding a lamb and singing a song that stops the latter girl. By the time Maria Josefa is put back to bed, Adela reenters with signs of having been out with Pepe. She and Martirio fight and all the women are called onstage. Adela triumphantly announces she will be Pepe's no matter what shame it brings, and Bernarda runs offstage with a shotgun to shoot Pepe. When Martirio enters to tell them Pepe is dead, Adela hangs herself, not knowing Martirio was only telling a cruel lie and that Pepe had actually escaped.
After they find the body, Bernarda has a short moment of remorse, after which she demands Adela be buried as a virgin no matter the truth demands again that the girls fall in line under her tyrannical strictures.