Personality hardiness, occupational stress, and burnout were investigated in 100 critical care nurses. Hardiness was predictive of occupational stress and burnout. Hierarchical multiple regressions revealed that one of the three dimensions of hardiness, commitment to work, was the only variable to account for significant amounts of variance (up to 24%) across three of four measures of burnout. The study did not provide support for the stress buffering effect of hardiness. That is, an interaction term, hardiness × occupational stress, was not convincingly predictive of burnout in nurses. The findings are discussed in terms of other research on burnout in critical care nurses and recent issues on the conceptualization of hardiness.