We examined whether combat-related PTSD was differentially associated with particular dimensions of anger on two multi-index, psychometric instruments and whether the proportion of variation in PTSD scores explained by anger was significantly greater than that by demographic and exposure variables. We also examined the reliability and validity of a subset of Mississippi Scale items as an anger measure. Participants were 143 Vietnam combat veterans. Anger accounted for over 40% of the variance in Mississippi PTSD scores (minus the anger items) above that associated with age, education, and combat exposure. Veterans with structured-interview-diagnosed PTSD were significantly differentiated from those without PTSD on all anger indices. The results point to anger treatment as a high priority for combat-related PTSD.