Purpose: Several studies have already provided valuable insights into the physiological and genetic causes of hyperglycemia and obesity. Concurrently, personality traits, such as hostility, have been suggested to have an impact on health and illness (i.e., self-reported general health, coronary artery disease, and overall mortality). The present systematic review investigated possible effects of hostility upon metabolic markers, such as high plasma glucose level and obesity among adults. We also attempted to reveal current gaps in knowledge and provide insights for future directions. Methods: This systematic review was performed following the PRISMA 2009 guidelines to examine current evidence arising from observational studies regarding the potential impact of hostile behavior on hyperglycemia and obesity among adults. Of the initial 139 articles, 13 studies were included. Results: The evidence supports an association between pre-diabetes and obesity with a hostile temperament in certain populations. The relationship between hostility and hyperglycemia was most common in African American women, in women with a family history of diabetes, in unmarried individuals, in White men, as well as in middle-aged and older people. Regarding obesity, high body mass index (BMI) was associated with a hostile personality, particularly among men. However, the paths by which hostile temperament affects glucose levels and BMI, as well as potential mediating and moderating mechanisms, are not entirely understood. Conclusions: There is a need for research to enhance the understanding of biological, psychological and social factors related to hostility with a view to prevention and effective intervention.