This study investigated effects of personal control on psychobiological stress responses. Salivary cortisol was used as an index of hypothalamic pituitary-adrenocortical axis response. Healthy males (N = 20) were exposed five times serially to a psychosocial stressor: mental arithmetic under time pressure. "Chance control", "other powerful controls" and "internality" were reported personality-dependent aspects of personal controls; "personal control as coping" under the psychosocial stress situation was also assessed with a questionnaire after the session ended. Cortisol response showed significant increase (F (16,304) = 6.69, p < 0.01). From the view point of personality, the high "chance control" score group showed higher levels of cortisol compared to the low score group before stressful tasks. On the other hand, the high "personal control as coping" score group showed higher levels of cortisol compared to the low score group after the stressful tasks. We inferred that the high "personal control as coping" score group conducted stressful tasks with high concentration and effort. The effects of such personal controls as personality and as ways of coping were demonstrated in this experiment through cortisol secretion in different stress-process phases.