This research aims to measure the prevalence of bullying in Japan. The agreed method used in bullying surveys, the operational classification method, has been employed. Furthermore a cluster approach was used to analyze the data, which was obtained by using the Negative Acts Questionnaire Revised administered to a consistent sample of Japanese workers. The results show that when comparing the traditional operational classification method with the two step cluster analysis there is a high overlap in identifying bullying victims and non victims. In addition bullying prevalence in Japan appears to be quite elevated, higher than several European countries. Significant differences on bullying exposure have been also found on a number of variables such as basic demographics, lifestyle and workplace factors Keywords: workplace bullying, Negative Acts Questionnaire Revised, negative behaviours, Japan.