In a document management apparatus and related document extracting method of the present invention, an operational history record of one of stored documents is generated every time an operation on the one of the stored documents is performed by a document operation device. The generated operational history records are stored. It is determined whether a selected item of the operational history record, stored for a currently processed document among the stored documents of the group, matches with a corresponding item of each of the operational history records, stored for the remaining ones of the stored documents other than the currently processed document, so that a list of related documents, which are related to the currently processed document, is extracted from the remaining ones of the stored documents, based on results of the matching.