OBJECTIVES: The personal and economic burden of diabetes is substantial and growing in Japan due to its aging population. This study aimed to review the available literature on the usual treatment of adults with type 2 diabetes (T2DM) in Japan. METHODS: Systematic search of the scientific literature was performed on MEDLINE and EMBASE databases to identify publications about usual care of diabetes in Japan written in English or Japanese and published between January 2000 and May 2013. Included keywords were diabetes mellitus, drug therapy and Japan. Randomized clinical trials, comparative or interventional studies were excluded. Of 17 publications that met search criteria, 13 pertained to adults with T2DM, of which 9 contained original survey data and 4 were literature reviews. RESULTS: Almost all of the available data was at least 7 years old. Based on data from 2000 to 2002, the use of oral anti-diabetic drugs (OAD) alone was the most prevalent treatment option (51.4%), followed by diet alone (25.4%), insulin alone (15.4%), and OAD with insulin (7.8%). Although overall, sulfonylureas was the preferred class of OAD (61-67%), its use among treatment initiators has dramatically declined from 40% to 22% following the introduction of dipeptidyl peptidase-4 inhibitors (DPP4) in 2009. Since then, the prescription rate of DPP4 increased to nearly 40% due to its perceived better safety. CONCLUSIONS: Available data on the treatment of diabetes in usual care in Japan is rather sparse and not recent. Results indicate that the treatment of adults with T2DM in Japan with OAD and insulin is rather similar to that in the US and Europe, although the specific OAD in Japan is different. Further research is needed on the usual treatment of diabetes in Japan, considering increased longevity, lifestyle changes, ongoing introduction of new medications, changes in disease management practices and increased economic concerns.