Shortly after World War II, in 1945–46, in one of the suburbs of Prague, Eda Souček attends a boys' elementary school where he belongs to a class with a complete lack of discipline. After the class drives their teacher Maxová to a mental breakdown during one of her classes, the schoolmaster has to implement special measures. A new male teacher, Igor Hnízdo, is employed, who is said to be a great war hero. Authoritative Hnízdo immediately introduces corporal punishment, which, as he explains, is not normally allowed but the school has received an exception from the Ministry of Education as a result of their dreadful behaviour. Despite his strict methods, the boys soon become charmed by the man. They love his battlefront stories and the fact that he is always armed and wears a uniform. Eda sees him as the very opposite of his own father, whom he considers to be too cowardly. Hnízdo makes the same positive impression on the townspeople. Nevertheless, his persona is also surrounded by many controversies. For example, his war heroism is disputed as he is unable to provide any accurate information about his military service. There is even an unconfirmed rumour that Hnízdo was only guarding goats during the war. But the boys from his class ignore all such criticisms and even fight those who are spreading the rumours. Hnízdo's reputation suffers after he is accused of having a sexual relationship with local twins who attend a girls' school in the same area. He is forced to leave because this is not the first time he has been involved in a similar affair. The formerly unmanageable boys begin to defend Hnízdo and call for his return. The accusation is finally withdrawn and Hnízdo comes back to the class. He states that the way they were dealing with the accusation is a proof that the physical punishments are no longer necessary.
The original story was written by Zdeněk Svěrák. He used his own experiences both as a pupil of a similar school and as a former teacher. This is the first of the films created by the successful father screenwriter - son director duo. The others include Akumulátor I., Kolja, Tmavomodrý svět and Vratné lahve. It was also the first non-documentary film by Jan Svěrák. Obecná škola is also notable because it includes one of the last roles for two prominent Czech actors Rudolf Hrušínský and Petr Čepek. The film was also the first appearance of Jan Tříska in a Czech film since his emigration to the United States in 1977.
