The play concerns a group of women, the leader of which is Praxagora. She has decided that the women must convince the men to give them control of Athens, because they could rule it better than they have been. The women, in the guise of men, sneak into the assembly and vote the measure, convincing some of the men to vote for it because it's the only thing they haven't tried yet.
The women then institute a proto-Communist government in which the state feeds, houses, and generally takes care of every Athenian. They enforce an idea of equality by requiring that every man sleep with every woman, starting with the oldest, and vice versa. This portrays a common view of women at the time: since they never owned anything and had to share everything, women were more likely to wish to own things in common than men, and were often seen as bing something of proto-Communists. The enforced equality is also something of a political statement in addition to being a social one. After the oligarchy put in place after the war fell, Athenians asserted their democracy and equality very strongly, to the point that, while it was a clear exaggeration, the play surely made its position on excessive democracy clear.
There is a scene in which two men are talking. One of them is going along with the new government, giving his property to the women, and obeying their orders. The other doesn't wish to give up his property, but he's more than willing to take advantage of the free food!
All the interesting threads of the play, unfortunately, go nowhere, and the play ends with a party scene that comes across as something of a non-sequitur.