The play begins with Praxagora emerging from a house on an Athenian street before daybreak. She is wearing a false beard, men's clothing, and is carrying a walking stick and a lit lantern. The chorus of Athenian women enter one by one, all dressed in similar costume. In order to be more convincing, some women developed tans and stopped shaving their armpits to appear more masculine. One woman brings a basket full of yarn in order to get some work done as the assembly fills up, to which Praxagora chastises her for this decision as it will ruin their cover.
The women are wary of the plan and Praxagora attempts to rally them as they practice speaking as men before the assembly. Praxagora is frustrated by the women's ability to pretend to be men, as they swear to Demeter and Persephone rather than Apollo, address the assembled women as ladies, and complain about the discomfort of their disguises and their thirst. Praxagora decides that she alone is capable of speaking to the assembly and practices a speech decrying the corrupt leaders of the city as selfish and unpatriotic through their acts of war and personal enrichment through public funds. She proposes that the men turn control of the government over to the women because "after all, we employ them as stewards and treasurers in our own households." She further explains that women are superior to men because they are harder workers, devoted to tradition and do not bother with useless innovations. As mothers, they will better protect the soldiers and feed them extra rations, as shrewd negotiators, they will secure more funds for the city. Praxagora impresses the women with her rhetorical skills, and explains that it was learned from listening to orators while living with her husband on the Pnyx, where the Athenian assembly was held. They discuss how they plan to handle opposition and practice how to raise their hands to vote before leaving to attend the assembly by dawn in order to receive pay and a complimentary meal. The chorus of women reiterate their intentions before exiting the stage.
Praxagora's husband Blepyrus emerges from their house wearing Praxagora's nightgown and slippers. He is old and desperately had to relieve himself but could not find his clothing in the dark. As he squats in the street lamenting his constipation, his neighbor arrives and both men realize that their wives and clothing are missing from their homes. Chremes, returning from the assembly, comes upon Blepyrus and his neighbor and explains that he was not paid because of the unprecedented turn-out of pale faced shoe-makers (referring to the women in disguise.) He relayed the events of the assembly and Praxagora's speech. Believing she was a "good-looking young man," Chremes explains how he argued women were better at keeping secrets, returning borrowed items without cheating, that they don’t sue or inform on people or try to overthrow the democracy, all points that Blepyrus agreed upon. Now free of attending the assembly, the men are pleased to finally sleep in, but are not excited about having to provide sex to receive their breakfast.
The chorus enters, still in disguise and on their way home from the assembly, trying not to draw attention to themselves. Blepyrus accuses Praxagora of sneaking off with a lover when he finds her returning his cloak. She explains that she was only helping a friend in labor and had to wear his cloak for warmth. She feigns surprise when he explains to her the decision from the morning's assembly, but immediately begins listing the reasons the decision was wise. Praxagora then goes on to explain the details of the new government to Blepyrus. She proposes banning all ownership of private wealth and establishing equal pay for all and a unified standard of living. She further explains that people will no longer have a need for personal wealth as all basic needs will be met by the common fund. She further adds that men and women will be free to sleep with anyone they want, so long as they first sleep with the uglier members of the opposite sex. Parental responsibilities will be shared by the community as children will no longer know their fathers. Slaves will work the fields and new clothes will be made when they are needed. Praxagora elaborates that there will be no more lawsuits, since there can be no debt in a society without private wealth. Punishments for assault will come out of the offender's bread ration and theft will be obsolete as all men will be given their fair share. Walls within homes will be knocked down and all will live in a common living space, courthouses and porticos will be turned into communal dining halls. Prostitutes will be put out of business, but slaves will be banned from sleeping with free men.
In the next scene, Blepyrus’ neighbor is laying his household objects out in front of his house to be contributed to the common fund as the Selfish Man enters. The Selfish Man calls the neighbor a fool for following the new laws. He plans on waiting to see if everyone else gives up their property before he does it himself, citing failed decrees from the assembly in the past. The town Herald enters and announces a lavish feast for all to attend. The Selfish Man acts entitled to the feast, but the neighbor points out his reluctance to donate possessions to the common fund disqualifies him from communal events. After the neighbor leaves to donate his possessions, the selfish man explains that he intends to keep his belongings and enjoy the free dinner at the same time.
In a different scene, a young girl waits for her boyfriend Epigenes to arrive as an old woman is out looking for a date. They exchange vulgar insults and go inside their homes as Epigenes enters the scene, lamenting the new laws governing sex. He and the girl both speak of their desire for one another, but are interrupted by the old woman. Citing the new law, the old woman attempts to force Epigenes to sleep with her first. As the young girl and the old woman fight over the boy, two more old women enter and drag him away against his will.
In the final scene, a drunken maid enters praising Thasian wine and the new laws. She is looking to bring Blepyrus to dinner at Praxagora's request. She finds Blepyrus passing by, already on his way to dinner with two girls in his arms. They all go to dinner together while the chorus sings of the lavish feast they are about to have.