This book tries to analyse postmodern characteristics in Douglas Adams's The Hitchhiker's Guide to the Galaxy in terms of postmodern structural features, mainly parody, irony, satire and laughter and their correspondences with science fictional qualities. Another question that will also be raised in the study is that whether postmodern qualities including ontological features, structural features (parody and so on) and the issues of alternative reality have an influence upon the way the book was shaped and handled as postmodern science fiction novel.