Director Jonny Owen's film was watched by a host of former Reds greats alongside supporters this weekend.
"There's something about that Nottingham Forest team, they stay in the popular consciousness of football fans across the world," said Mr Owen, quoted on the BBC.
"Everybody you speak to across the country go 'what a side they were' and 'what a story that was'."
I Believe in Miracles will be released in cinemas nationwide on Tuesday and on DVD and Blu-ray from 16 November.