Background: Shift work with sleep disruption is a systemic stressor that may possibly be associated with blood pressure dsyregulation and hypertension. Purpose: We hypothesize that rotation to a simulated night shift with sleep deprivation will produce blood pressure elevations in persons at risk for development of hypertension. Method: We examined the effects of a simulated night shift on resting blood pressure in 51 diurnal young adults without current hypertension. Resting blood pressure was monitored throughout a 24 hour period of total sleep deprivation with sustained cognitive work. Twelve participants (23.5%) reported one or more parents with a diagnosis of hypertension. Ten participants were classified as prehypertensive by JNC-7 criteria. Only two prehypertensive subjects reported parental hypertension. Results: Results indicate that as the night shift progressed, participants with a positive family history of hypertension showed significantly higher resting diastolic blood pressure than those with a negative family history of hypertension (p=.007). Prehypertensive participants showed elevated blood pressure throughout the study. Conclusions: These data suggest that rotation to a simulated night shift with sleep deprivation may contribute to blood pressure dysregulation in persons with a positive family history of hypertension.