The present study examined whether salivary cortisol secretion as an index of stress reactivity to continuous mental task performance reflected individual differences in coping styles. During 4 hr of continuous mental tasks significantly higher cortisol levels were found in comparison with a control session. However, individual variability in the cortisol response was high. Correlational data indicate a significant negative relationship between the coping style 'comforting cognitions' and the individual cortisol response during mental stress. During this particular type of cognitive stress, where the subject has no control over the experimental situation, comforting and emotion-focused coping may be effective because of the subject's efforts of trying to reframe the inevitable situation in a positive and self-encouraging way. In contrast, there was no significant relationship between trait anxiety and individual glucocorticoid susceptibility to mental stress.