The present paper focuses on the section in dictionary entries that gives the word class or part of speech of the headword. It first reviews the previous studies done in the field of lexicography on presenting the word class in dictionaries, then focuses on word class in Japanese, and introduces its major issues. This paper also reports a survey done by the authors to investigate the approach taken by existing bilingual dictionaries to deal with the problems of presenting the word class in Japanese dictionaries. This study analyzes the solutions provided by these dictionaries based on the needs of Japanese language learners. Finally, based on the survey, this paper makes concrete suggestions on how a Japanese learners' bilingual dictionary should present information on the word class of its headwords.