We tested the job demands--job control model of stress with a group of 136 registered nurses. Significant interactions between subjective and objective measures of work load and a measure of perceived control predicting physiological and attitudinal outcomes indicated support for the model. In addition, objectively assessed job demands were significantly associated with blood pressure and cortisol levels. The model also predicted elevations in physiological responses after individuals left work, suggesting that potentially health-impairing reactions to jobs that have high demands and low controllability might carry over to home settings and thus pose a high risk of long-term health impairment. The results have implications for the role of personal control in occupational stress generally and for nurse-management practices specifically.