Background Family history of hypertension is a primary predictor of high blood pressure (BP). This study attempted to determine whether there is a gradual increase in BP between individuals with two hypertensive parents, one hypertensive parent, and normotensive parents and whether this increase is apparent with both ambulatory and casual BP assessments in men as well as in women. Methods A total of 220 healthy men and women, aged 22 to 50 years, completed two 24-h ambulatory BP sessions (one work day and one off work day). Based on family history information obtained from parents, three groups were formed: subjects with two hypertensive parents, one hypertensive parent, and normotensive parents. Work and off work days did not differ; analyses were based on mean values of the 2 days. Results Men with two hypertensive parents had higher daytime and night-time ambulatory BP than men with normotensive parents. Those with one hypertensive parent had intermediate BP levels. Ambulatory BP was not associated with family history in women. Also, men with one or two hypertensive parents had higher ambulatory BP than women with hypertensive parents, whereas offspring of normotensive parents exhibited no sex differences in BP. Conclusions Elevated systolic and diastolic BP throughout the day and night seems to characterize men with two hypertensive parents. In evaluating the relationship between family history of hypertension and BP, it is important to use ambulatory BP measures, differentiate between individuals with one and with two hypertensive parents, and focus on gender differences in BP.