Set in the period of the Japanese Occupation in Malaya during World War II, Sergeant Hassan is a wartime drama made by two prominent filmmakers of the time — P. Ramlee from Singapore and Lamberto Avellana from the Philippines. It follows the trials and tribulations of an adopted boy, Hassan (played by P. Ramlee himself), who rises up to the challenges of life while serving his people as a sergeant in the Malay Infantry Regiment. The film shows the hardships suffered by the Malay people during the dark days of the Japanese Occupation, explores the sensitive issue of Japanese collaborators and asks whether the people should fight or cooperate with an invading army. As with most wartime films, the qualities of honour, loyalty and integrity are tested in this story through the characters of Hassan, his step-brother, a Malay-Japanese collaborator named Buang, and the infamous Kempeitai (Japanese police). The passionate performance given by both the lead actor and the supporting cast shows exactly why the Malay movie industry flourished in the 1950s and why Sergeant Hassan is considered one of P. Ramlee's _nest works. The film was directed by Lamberto Avellana, but he left midway through the filming and P. Ramlee took over. However, Ramlee decided to give him full credit.