A temporary stage has been set up outdoors on Sorin’s large estate. Sullen, black-garbed Masha, the daughter of the estate manager, is followed by Medvedenko, a schoolteacher. Medvedenko expresses his unrequited love for Masha, who informs him, “I am touched by your affection, but I cannot return it.” Sorin, the estate’s owner and a retired civil worker in poor health, enters, leaning heavily on his cane. He is accompanied by his nephew, the aspiring playwright Konstantin, who anxiously shoos Masha and Medvedenko away so that he can have quiet to put the finishing touches on his play.
Once they have left, Konstantin admires the setting and the stage; it is perfect for his vision of a contemporary, unconventional theatre. He informs Sorin that a young woman named Nina, who lives across the lake, will be playing the lead role in his play — a fact that enrages Konstantin’s mother, Arkadina, a famous actress.
Nina, lovely and nervous, rushes in, excitedly, and Konstantin sends Sorin away to fetch the audience. Alone, Nina and Konstantin kiss. Nina confesses that she is nervous to perform in front of Arkadina and her lover, the famous author Trigorin. Konstantin reassures her. as the audience — Sorin, Shamrayev, the estate manager and his wife Paulina, Dorn, a doctor, and finally Arkadina and Trigorin — file in.