The teaching of posterior composites has undergone considerable refinement and development in western countries in recent years. However, little information exists on this teaching in other parts of the world. The aim of this paper is to investigate the teaching of posterior composites to undergraduate dental students in Japan. In late 2007/early 2008, a questionnaire seeking information on the teaching of posterior composites was distributed by email to the person responsible for teaching operative dentistry in each of the 29 dental schools having undergraduate dental degree programmes in Japan. Twenty-three completed responses were returned (response rate = 79%). While all 23 schools taught the placement of composite in occlusal cavities in premolars and molars, 7 schools did not teach the placement of two-surface occlusoproximal composites in premolars (n = 1) and molars (n = 6) and 14 schools and 15 schools do not teach placement of three surface occlusoproximal composites in premolars and molars, respectively. While composite at the time of the survey accounted for 45% of posterior direct restorations placed by students, it is anticipated that this proportion will increase to 59% in 5 years time. Variations were noted between schools in the teaching of principles of cavity design, techniques for restoring proximal contours and light-curing technologies; however, more consistency was observed in techniques used for protecting operatively exposed dentine than that observed in western countries. Despite variations between dental schools being noted in the teaching of certain techniques for posterior composites, the overall extent and content of teaching of posterior composites in Japan could be described as comparable, if not exceeding, than that observed in western countries.