There is considerable evidence for the effectiveness of Motivational Interviewing (MI) in the treatment of substance abuse, as well as a number of other health behavior areas. The present paper summarizes and critically reviews the research in three emerging areas in which (MI) is being applied: diet and exercise, diabetes, and oral health. Although 10 prior reviews focused in part on MI studies in the areas of diet, exercise, or diabetes, the present paper provides an up-to-date review, and includes oral health as another emerging area of MI research. Overall, 37 articles were reviewed: 24 in the areas of diet and exercise, 9 in the area of diabetes, and 4 in the oral health area. Research in these areas suggests that (MI) is effective in all these health domains, although additional research is needed, particularly in the oral health arena. Specifically, future research in the areas of diet and exercise should examine the clinical utility of MI by health care professionals (other than dietitians), studies in the area of diabetes should continue to examine long-term effects of MI on glycemic control, and research in the area of oral health should focus on developing additional trials in this field. Further, future studies should demonstrate improved research methodology, and investigate the effects of possible outcome mediators, such as client change talk, on behavior change.