Background:Severe cognitive decline is one of the major public health problems in developed countries. Finding modifiable risk factors could become essential to develop strategies to prevent or delay dementia progression and stop its rising incidence. Objective:Our aim was to investigate the association between hypertension and cognitive function and to assess whether better adherence to the Mediterranean diet may modify this association. Methods:A subsample of 764 participants from the 'Seguimiento Universidad de Navarra' (SUN) cohort older than 55 years was evaluated with the Spanish Telephone Interview for Cognitive Status (TICS-m) at two-time points, separated by 6 years. Multivariable-adjusted linear regression models were used to prospectively assess the association between hypertension -also according to adherence to the Mediterranean diet- and 6-y changes in cognitive function. Results:The adjusted between-group difference in the 6-year change of the TICS-m score between hypertensive participants and their non-hypertensive counterparts was -0.36 (95% CI -0.70, -0.02). This association was stronger among participants with a lower adherence to the Mediterranean diet [-0.62 (95% CI: -1.09, -0.15)] but the differences between hypertensive and non-hypertensive participants were no longer significant among participants with a higher baseline adherence to the Mediterranean diet. Conclusion:In this Mediterranean cohort, hypertension was inversely associated with cognitive function, but an attenuation of this detrimental association by a moderate/high adherence to the Mediterranean diet was suggested.