Němec’s career as a filmmaker started in the late 1950s when he attended FAMU, the most prestigious institution for film training in Czechoslovakia. At this time, artistic and public expression was subject to censorship and government review. However, thanks largely to the failure of purely propagandist cinema in the early 1950s and the presence of important and powerful people within the Czechoslovak film industry, the 1960s led to an internationally acknowledged creative surge in Czechoslovak film that became known as the Czech New Wave, in which Němec played an instrumental part.
As a graduation film, Němec adapted a short story by Arno¨t Lustig based on the author’s experience of the Holocaust: « A Loaf of Bread » (« Sousta »). Němec would return to Lustig’s writing when he directed the influential film, « Diamonds of the Night » (« Démanty noci », 1964), which was also based on the Holocaust. The film follows the fate of two boys who escape from a transit train to a concentration camp. It is noted for its dramatic subjectivization of the experience of the Holocaust using experimental techniques, including flashbacks, simulated hallucinations and an unusual double ending that leaves the viewer in doubt as to the fate of its protagonists. It was his first major success, and while it passed the censors’ reviews, it helped lay the foundation for the political movement that was coming. More importantly, it remains an aesthetic and technical milestone in the exploration of human experience under extreme conditions.
His best known work is « A Report on the Party and the Guests » (« O slavnosti a hostech, 1966 »). Its plot revolves around a group of friends on a picnic who are invited to a bizarre banquet by a charismatic sadist, played by Ivan Vyskočil, who eventually bullies most of them into blind conformity and brutality while those who resist are hunted down. The film particularly received a bad reception from the authorities as Vyskočil in the film had a remarkable likeness to Lenin, though according to Peter Hames this was accidental. Moreover, the cast consisted of many dissident Czechoslovak intellectuals of the day. The film was viewed as being so subversive to the Communist state that Antonín Novotný, the President, was said to « climb the walls » on viewing it and Němec’s arrest for subversion was considered.
However, before the political fallout from « A Report on the Party and the Guests » was able to take effect, he was able to have approved one more feature: « Martyrs of Love » (« Mučedníci lásky », 1966). The film, perhaps in mind of the previous troubles he had suffered, was completely apolitical, but it’s surrealist lyrical style did not endear it to the authorities and Němec was forced to work outside the government-approved system, producing the film « Mother and Son » (« Mutter und Sohn », 1967), which won an award at the Oberhausen Film Festival.
His next important feature was a documentary, « Oratorio for Prague », of the Soviet-led invasion of Prague in 1968, which ended the liberal Prague Spring. It was banned, but Němec’s footage would eventually be used by countless international news organizations as stock footage of the invasion.
After 1968, he left Czechoslovakia for Germany before eventually moving to the United States.