There have been many papers examining the relationship between blood pressure and birthweight but although the association is clearly established in adults and children findings in adolescence and young adults have been inconsistent. The objective of this study was to examine the relationship between blood pressure and birthweight in young adults. The blood pressure of 1358 university students aged 18-25 was recorded at a screening medical examination and their birthweight from parental report. Using linear regression analysis, systolic blood pressure, after adjustment for age, weight and height, decreased by 2.00 mmHg (-3.8, -0.2) for every kg increase in birthweight in females. The relationship was negative but non-significant in males. Substituting body mass index (BMI) for weight in the regression analysis produced similar results. There was a smaller and non-significant relationship between diastolic blood pressure and birthweight which is consistent with other studies. This study confirms the inverse relationship between systolic blood pressure and birthweight in young adults and provides some support for the hypothesis that undernutrition in utero contributes to the development of cardiovascular disease in adults.