Objectives To characterize information on diabetes prevention appearing in Japanese general health magazines and to examine the agreement of the content with that in clinical practice guidelines for the treatment of diabetes in Japan. Methods We used the Japanese magazines’ databases provided by the Media Research Center and selected magazines with large print runs published in 2006. Two medical professionals independently conducted content analysis based on items in the diabetes prevention guidelines. The number of pages for each item and agreement with the information in the guidelines were determined. Results We found 63 issues of magazines amounting to 8,982 pages; 484 pages included diabetes prevention related content. For 23 items included in the diabetes prevention guidelines, overall agreement of information printed in the magazines with that in the guidelines was 64.5% (471 out of 730). The number of times these items were referred to in the magazines varied widely, from 247 times for food items to 0 times for items on screening for pregnancy-induced diabetes, dyslipidemia, and hypertension. Among the 20 items that were referred to at least once, 18 items showed more than 90% agreement with the guidelines. However, there was poor agreement for information on vegetable oil (2/14, 14%) and for specific foods (5/247, 2%). For the fatty acids category, “fat” was not mentioned in the guidelines; however, the term frequently appeared in magazines. “Uncertainty” was never mentioned in magazines for specific food items. Conclusion The diabetes prevention related content in the health magazines differed from that defined in clinical practice guidelines. Most information in the magazines agreed with the guidelines, however some items were referred to inappropriately. To disseminate correct information to the public on diabetes prevention, health professionals and the media must collaborate.