A square in the ancient Russian town of Putivl. Prince Igor together with his son Vladimir and the prince´s armed force of warriors is getting ready for a campaign against the nomadic Polovtsians who devastate the Russian lands by their rapacious raids. People greet Igor and other princes and warriors and wish them victory. It suddenly gets dark – a solar eclipse begins. The people and boyars regard this as an ill omen and advise Prince Igor to put off the campaign. Igor´s wife Yaroslavna also implores him to stay at home. But Prince Igor is unbending. He is sure that his cause is right – he is going to defend his native Russia.
The prince says goodbye to his wife, tenderly consoles her and assures her that she need not worry about him and should await his victorious return. He entrusts Yaroslavna to the care of her brother, Prince Vladimir of Galich, whom he leaves as his deputy in Putivl during his absence.
Two warriors, Skula and Yeroshka, secretly leave Prince Igor´s army. They want to join the service of the Prince of Galich.
After their blessing, Prince Igor and his detachment set off for the campaign.
The courtyard of Prince Vladimir of Galich.
The Prince of Galich is feasting at a lavishly laid table, with his servants led by Skula and Yeroshka carousing nearby. Prince Vladimir of Galich is eager to extend his power. He wants to confine Yaroslavna in a convent and become the Prince of Putivl by dethroning Prince Igor.
Agitated maidens run into the courtyard. They beg the Prince of Galich to liberate their girl-friend who was placed by warriors in the terem palace for amusement. But the prince drives the maidens out to the laughter of the drunken crowd.
The drinking-bout reaches its culmination. Skula and Yeroshka, together with the warriors, whose boldness grows after drinking, conspire a mutiny: "We shall depose Igor and elevate Vladimir to the throne! What are we to be afraid of?"
The main room in Yaroslavna´s terem palace.
The princess feels uneasy. Troublesome dreams and bad presentiments do not leave her, neither in the daytime nor during the night. She has had no news from the prince for a long time. And she sees the strife around her made by the princes. Even her brother Vladimir has conceived some evil deed hoping to dethrone Prince Igor and to become the prince of Putivl.
The girls driven out by the prince from the courtyard suddenly arrive and distract Yaroslavna from her sad thoughts. The girls implore the princess to defend them from their abuser. Yaroslavna accuses her brother of treason, but she cannot deal with him. Called by the princess to answer, the Prince of Galich conducts himself impertinently, threatening her and Prince Igor.
The boyars come in and announce that Igor´s army has been defeated and the prince himself imprisoned. The Russian princes wallow in dissent, while hordes of the Polovtsians are coming to Russia. Disturbed by what she has heard, Yaroslavna wishes to interrogate the messengers herself. Meanwhile the Prince of Galich and his servants, using the moment to their advantage, stir up a rebellion. The alarm bell is heard – the Polovtsians are approaching Putivl. The boyars and people are resolute to defend their land from the enemy.
Evening in the Polovtsian Camp. The Polovtsian maidens are trying to amuse Konchakovna, the daughter of Khan Konchak, with songs and dances. Her thoughts are concentrated on the captive youth – Prince Igor´s son Vladimir. Konchakovna impatiently waits to see him.
Tired Russian captives are passing by from their hard labour. Prince Igor and his son Vladimir are among them. The youth sees Konchakovna for the first time and her beauty charms him.
Prince Igor cannot fall asleep. He is oppressed by dark thoughts. It is not easy to overcome the shame of defeat and captivity and no less difficult to accustom himself to the thought of his native land being inslaved. Igor passionately yearns for freedom in order to liberate Russia. He tenderly recalls his beloved wife Yaroslavna.
Suddenly Ovlur, a baptized Polovtsian, comes to him. He offers Igor help to escape. But Prince Igor refuses – the Russian king ought not to run away stealthily.
The Polovtsian Khan Konchak bestows Igor with high honours. He promises to free him if he promises never to raise his sword against the Polovtsians.
The pride and valour of the Russian prince delight Konchak.
On the khan´s orders, the captive women and warriors entertain Igor to dispel his gloomy thoughts by their dances glorifying the mighty Konchak.
The Town Wall at Putivl. Yaroslavna, on losing any hope for Igor´s return, laments for him in the morning. Addressing the wind, the sun and the River Dnieper, she awaits an answer about Igor. Where is he and what has happened to him? The inhabitants´ sad song bewailing the desolated and burnt out land echoes Yaroslavna´s cry.
Suddenly the princess notices two horsemen in the distance – Prince Igor and Ovlur. So her husband has returned at last!
The drunken Skula and Yeroshka, who do not know about the prince´s return, are mocking their captivated prince. They are quite taken aback on meeting him suddenly. In order to evade severe punishment, Skula suggests to Yeroshka to be the first on the bell-tower and strike the bell announcing the prince´s arrival. On hearing the sounds of the bell people run to the square. They are glad to meet Prince Igor and greet him as well as the other princes arriving in Putivl and are ready to unite.