OBJECTIVE To test the hypothesis that there is a prospective association between constitutional hypotension and new-onset fatigue in a large, representative sample. METHODS In this prospective study using a large population-based cohort dataset, the Health and Lifestyle Survey, a representative sample of the population residing in private dwellings in Great Britain in 1984 (n=9003, ages 18-97 years) had their blood pressure measured and were asked about fatigue. Participants reporting fatigue at baseline were excluded. The outcome was fatigue state in 1991. RESULTS No association was shown, unadjusted or adjusted for likely confounders, in the healthy young population [systolic BP: adj. OR (95% CIs)=1.25 (0.90-1.74); diastolic BP: 1.18 (0.84-1.65)] or the whole population [systolic BP: 0.98 (0.77-1.26); diastolic BP: 1.01 (0.79-1.26)]. CONCLUSION In this British population-based study, hypotension was not a risk factor for incident idiopathic fatigue.