INTRODUCTION AND OBJECTIVES:The use of aspirin and non-aspirin analgesics has been associated with changes in blood pressure. The aim of this study was to investigate prospectively the association between the regular use of aspirin and non-aspirin analgesics and the incidence of hypertension. METHODS:The SUN project is an ongoing, continuously expanding, prospective cohort of Spanish university graduates initially free of hypertension, cardiovascular disease, diabetes and cancer; 9986 (mean age 36 years) were recruited during 1999-2005 and followed up for a mean of 51 months. Regular aspirin and non-aspirin analgesic use and the presence of other risk factors for hypertension were assessed by questionnaire at baseline, and the incidence of hypertension was assessed using biennial follow-up questionnaires. RESULTS:In total, 543 new cases of hypertension were identified during follow-up. Regular aspirin use (i.e. 2 or more days/week) was associated with a higher risk of hypertension (hazard ratio=1.45; 95% confidence interval, 1.02-2.04) after adjustment for various confounding factors. Regular use of non-aspirin analgesic drugs was also associated with a higher risk of hypertension (hazard ratio=1.69; 95% confidence interval, 1.28-2.23). CONCLUSIONS:The regular use of aspirin and non-aspirin analgesics were both associated with an increased risk of developing hypertension, independently of other risk factors.