Background: Omega-3 fatty acids (n-3 FA) may have blood pressure (BP)-lowering effects in untreated hypertensive and elderly patients. The effect of n-3 FA on BP in young, healthy adults remains unknown. The Omega-3 Index reliably reflects an individuals' omega-3 status. We hypothesized that the Omega-3 Index is inversely associated with BP levels in young healthy adults. Methods: The current study (n=2036) is a cross-sectional study investigating the baseline characteristics of a cohort, which includes healthy adults, age 25-41 years. Individuals with cardiovascular disease, known diabetes or a BMI higher than 35kg/m(2) were excluded. The Omega-3 Index was determined in whole blood using gas chromatography. Association with office and 24-h BP was assessed using multivariable linear regression models adjusted for potential confounders. Results: Median Omega-3 Index was 4.58% (interquartile range 4.08;5.25). Compared with individuals in the lowest Omega-3 Index quartile, individuals in the highest had a SBP and DBP that was 4 and 2mmHg lower, respectively (P<0.01). A significant linear inverse relationship of the Omega-3 Index with 24-h and office BP was observed. Per 1-U increase in log-transformed Omega-3 Index the lowering in BP (given as multivariable adjusted coefficients;95% confidence interval) was -2.67mmHg (-4.83;-0.51;P=0.02) and -2.30mmHg (-3.92;-0.68;P=0.005) for 24-h SBP and DBP, respectively. Conclusion: A higher Omega-3 Index is associated with statistically significant, clinically relevant lower SBP and DBP levels in normotensive young and healthy individuals. Diets rich in n-3 FA may be a strategy for primary prevention of hypertension.