A method and system to print a document with a related document are provided. A frequently used document can be stored in a printer as a related document. A document and searching information on the document is transmitted to the printer. The related document of the document is searched among the documents stored in the printer by using the searching information, and displayed. At least one of the displayed related documents is selected by a user and printed together with the document. This results in greater convenience to the user because the user does not need to individually find a corresponding related document for printing.