Although the children are said to be chased in Athlone the streets were actually in Athenry town.
Jack Wild had to wear a red wig throughout filming as he refused to have his hair dyed ginger. Upon seeing the wig, which was permed, Wild immediately started to regret not having his hair dyed.
The song "You Don't Have to be Irish to be Irish" was a main feature of the 1971 St Patrick's Day Parade on Fifth Avenue in New York.
Cast members Ron Moody and Jack Wild in this film were reunited from Oliver! (1968) where they had about three years earlier played Fagin and the Artful Dodger respectively. The pair also later both appeared in Moussaka & Chips (2005).