How many movies have Gam Lau and Ng Yat-Siu collaborated on?

They have worked on 3 movies together! Their first movie together was The Story of Wong Fei-Hung, Part 4: The Death of Liang Huan (1950) and was their highest rated movie together. They have not worked together since Silk Factory Girl (1955). They are most known for their drama films together.