1. Remember the scene where Kevin places the loose tarantula on Marv's face and Marv lets out a girly high-pitched scream? Well the scream was dubbed in the edit as Daniel Stern, who played Marv, was afraid of screaming at the spider in case it bit him. He mimed the scene.
2. When Harry and Marv manage to get their hands on Kevin they hang him from his jumper on a coat hook in the kitchen. Harry threatens to bite off each one of Kevin's fingers but is intercepted by Old Man Marley who saves the day. But, what the audience didn't realise was that Joe Pesci actually did bite Macaulay's finger and left a permanent scar.
3. Robert De Niro and Jon Lovitz reportedly turned down the role of Harry. Interestingly the name of the character, Harry Lime, was named after Orson Welles's character from the film The Third Man.
4. The picture Kevin finds of Buzz's girlfriend was actually a picture of a boy made up to look like a girl. The famous scene where Kevin shouts 'woof' upon seeing the photo meant that producers felt it would be mean to make fun of a girl like that. The art director's son volunteered to be dressed as a girl.
5. We're all aware of the conspiracy theories about Elvis Presley still being alive. Well many of those who believed this were convinced that Elvis had a cameo role in Home Alone. They thought the man standing behind Mrs. MacCallister in a queue was Elvis.
6. At the beginning of the movie Kevin's Dad accidentally throws away Kevin's plane ticket after cleaning up the kitchen. This would explain why they never realised Kevin was missing at the airport because they didn't have his ticket at check in. Mind Blown!
7. Kevin's bed wetting younger cousin, Fuller, was actually played by his younger brother Kieran and it was his very first acting job. He later went on to become a successful child star himself.
8. When Marv climbs through the window, bare footed, he steps on loads of Christmas ornaments. Fortunately for the actor they were made out of candy and so didn't cause too much damage.
9. The idea for the movie came from another movie, Uncle Buck. In one particular scene Miles Russell, played by Macauley, interrogates a babysitter through the letterbox. Screenwriter John Hughes was inspired by the movie and the role of Kevin was written with Macauley in mind.
10. The poster for the movie has an image of Kevin with his hands on his face and screaming. It's based on the famous painting "The Scream" by Edvard Munch.
