Evidence links the personality trait hardiness to both mental (MH) and physical health (PH) status, but few unifying models delineate interrelationships of these variables. The first purpose of this study was to examine the association of hardiness to MH and PH in military men. Second, we tested the hypothesis that MH would mediate the association of hardiness with PH. Identical measures were collected in two separate, demographically-similar samples (n = 65 and n = 55). All subjects completed a background questionnaire, the Dispositional Resilience Scale-15 and the Short Form 36 Medical Outcomes Survey. Associations between hardiness, PH and MH were examined using regression-based mediation analyses followed by the Sobel test of indirect effects. In the total sample, hardiness predicted PH in an initial regression model (β = 0.37, p < .001). When MH was added to the model, however, PH’s influence was substantially attenuated and no longer significant (β = 0.06, p > .05). A Sobel test of significance confirmed a mediated effect (p < .001). Similar patterns were observed in each individual sample. Hardiness is associated with PH in military men, and this relationship is mediated by MH