Recent evidence suggests that individuals with certain personality traits are at elevated risk for chronic systemic inflammation. To date, this literature has focused on the related traits of hostility and negative affect (NA). In this study, we examine the covariation of trait measures of hostility and NA with the inflammatory mediators interleukin-6 and C-reactive protein. We also explore whether observed associations reflect independent contributions of cognitive, affective and behavioral components of hostile dispositions or shared trait variance with global negative affectivity. Subjects were a diverse sample of 855 relatively healthy middle-aged community volunteers (50% male) from the Adult Health and Behavior Project. The Buss and Perry Aggression Questionnaire (BPAQ) and an Abbreviated Cook-Medley Hostility Scale (ACM) were used to measure dimensions of hostility, and the Multidimensional Personality Questionnaire was used to measure trait NA. Regression analyses accounting for demographic characteristics and medical covariates showed a positive relationship of all components of hostility and trait NA with both IL-6 and CRP. After controlling for trait NA, only the behavioral component of hostility was independently associated with the inflammatory markers. The relationships of cognitive and affective components of hostility with inflammatory markers were largely explained by lifestyle factors, particularly body mass index and smoking. In contrast, lifestyle factors did not explain the covariation of hostile behavioral tendencies and inflammation. These findings suggest that unique attributes of aggressive behavioral tendencies account for much of the variability in inflammation associated with hostility and negative emotions, raising the possibility that individuals high in aggression are at increased risk of inflammatory disease.