Visit the IMDB homepage by typing "www.imdb.com" into your browser's web address bar.
Locate the search field at the top of the web page. Make sure that the first drop-down field is selected on "all." In the field to the left of the "all" field, type the name of the movie you wish to find the IMDB number for. Press "Go" when finished.
Choose the correct film or television show from the list of search results. Your choice will usually be the first selection on the screen. However, if the film you are searching for is more obscure or there are multiple films with the same name, you may have to inspect the results for the correct selection. A couple ways you can easily find the correct film is by identifying the release date, country of origin or the poster art.
Look at the address bar in your browser when you are on the correct movie's IMDB page. The url will look like the following: "http://www.imdb.com/title/tt0123456/." The IMDB number is the number located at the end of the url, including any zeros. Ensure that you omit the "tt" when referring to the number as well. The number can be used to quickly reference a movie or to cross check films on other movie sites that use the IMDB number system.