This study was a five-year follow-up of women who had participated in a previous experiment. At time one, we obtained measures of hardiness, Type A behavior, locus of control, stress, illness, and physiological reactivity. At time two, we obtained measures of illness for the past twelve months. Multiple regression analyses support the hypotheses that both hardiness and locus of control buffer the effects of stress on illness. Furthermore, Type A classification was associated with greater illness frequency and resting systolic blood pressure predicted future health status. An examination of all variables simultaneously revealed that future illness frequency is best predicted by locus of control x stress, high resting systolic blood pressure and low systolic reactivity. Future illness severity was best predicted by locus of control and resting systolic blood pressure. These results support the hypotheses that hardiness and locus of control buffer the effects of stress on health in women employed as clerical workers; however, the predictive power of hardiness in these women is largely accounted for by the contribution of locus of control.