Grierson was a member of the jury for the Canadian Film Awards in 1970. He spent a few months in 1971, travelling around India instilling the importance of having small production units throughout the country. He returned to the UK in December 1971 and was meant to travel back to India; however, his trip was delayed by the Indo-Pakistani War. Grierson went into hospital for a health check-up in January 1972; he was diagnosed with lung and liver cancer and was given months to live. During his time in hospital he spent time dictating letters to his wife, Margaret, and received visitors; however, he fell unconscious on 18 February and died on the 19th. In his wishes for his funeral he had detailed his desire to be cremated. Also according to his wishes, his urn was placed in the sea off the Old Head in Kinsale, and his brother Anthony, who had died in August 1971, had his ashes placed at the same time. A small flotilla followed the "Able Seaman", which carried the ashes, and when the urns were lowered into the water, the fishing boats sounded their sirens.