The moviemaker, Todd Phillips, had originally intended to call the new comedy "The Hangover 2", but he subsequently changed the titled to "The Hangover: Part II".
He has now confirmed the title is a deliberate reference to "The Godfather: Part II" - which famously won more Academy Awards than the 1972 original.
Todd Phillips tells MTV.com, "I think there are very few sequels that have been made that live up to or exceed their first film. The Godfather is the first one. We had always planned on calling it 'The Hangover 2', and when we finished the script, I changed the cover page and wrote 'The Hangover: Part II', because I think the film lives up to or exceeds the first one. It was very much a nod to 'The Godfather'."