Leporello voices his dissatisfaction with his employment as a servant of Don Giovanni. While his master is enjoying an amorous adventure with the beautiful Donna Anna, all he has to do is to keep cave for him. Giovanni rushes out of the house, pursued by Anna trying to hold him back. Anna’s father, the Commendatore, intervenes, and it comes to a swordfight in which he is killed by Giovanni. Anna has called her fiancé Don Ottavio to her help, and together they discover the body of the Commendatore. Anna calls upon Ottavio to avenge her father’s death. Giovanni is meanwhile after new adventures. He meets Donna Elvira, to whom he had promised marriage. She has come to hold him to this promise. Giovanni manages to slip away while Leporello distracts her attention by reciting to her the long list of Giovanni’s amorous conquests. Giovanni comes across the rustic wedding party of Masetto und Zerlina. Between Giovanni and Zerlina sparks fly immediately. In order to seduce her at his leisure, Giovanni invites the whole party into his mansion and tells Leporello to divert Masetto’s attention. Left alone with Giovanni, Zerlina promptly falls for his charms and for the prospect of climbing the society ladder through him. Donna Elvira warns Zerlina not to believe anything Giovanni promises her. In the presence of Donna Anna and Don Ottavio she declares Giovanni to be a ruthless deceiver. Giovanni manages to hustle her out and to apologize to the others for her behaviour. Anna tries to make her fiancé see her as a victim of Giovanni’s wiles. Leporello reports to his master how he distracted Masetto. Zerlina does her best to soothe Masetto’s jealous animosity. Ottavio appears with Anna and Elvira, intent on challenging Giovanni to account for himself, and Leporello promptly invites them to put on masks and to come to a party in the name of freedom. Don Giovanni comes across Zerlina again and entices her away from the others; while Leporello struggles to keep the incensed Masetto from going after them, Zerlina’s voice is heard crying for help. Giovanni tries to make out that it was Leporello who was harassing her, but fails to convince and is denounced for his misconduct; hinting that they are the real hypocrites, Giovanni defies them and makes his escape.
Leporello wants to give up his employment, but Don Giovanni persuades him to stay on. He has his eye on Donna Elvira’s maid. He orders Leporello to exchange clothes with him and to keep Elvira occupied while he makes a go for the girl. Masetto thinks it is to Leporello that he is confiding his intention to kill Giovanni, but then Giovanni reveals his identity and gives him a sound beating, leaving it to Zerlina to patch up her battered beau. Donna Anna, Don Ottavio, Masetto and Zerlina take Leporello to task for supporting his master’s escapades. After a few words in his own defence Leporello manages to slip away. While Giovanni recites to Leporello with relish what he has been up to, an uncanny voice is heard. Leporello notices that they are standing by the statue on the Commendatore’s grave. Backed up by Leporello, Giovanni jokingly invites the statue to dinner. Don Ottavio, standing with Anna beside her father’s grave, presses her to consent to marry him. She is evasive. Don Giovanni’s celebration of freedom is in full swing again. Donna Elvira makes another attempt to appeal to his conscience, but Giovanni will have none of it. The feast is interrupted by a higher instance which challenges Giovanni to repent of his sins. His refusal to give way is the end of him. His annihilation leaves a gap in society which not least poses the question of how they are going to get on without him.