Previous studies evaluating the association between arterial blood pressure and venous thromboembolism (VTE) reported conflicting results. The relationship between antihypertensive therapy and VTE has never been specifically evaluated. This report from a hospital-based case-control study included 785 cases with confirmed unprovoked VTE and their 785 age- and sex-matched controls. Cases and controls were asked for drug exposure in a one-to-one standardized interview using the same questionnaire. Drug exposure was defined as current use of drugs at admission with onset at least 1 week ago. Three hundred and eighty-four out of 785 cases (48.9%) and 379 out 785 controls (48.3%) reported that they were currently using at least one antihypertensive drug. Among all antihypertensive therapies, only angiotensin II receptor blockers were significantly associated with a reduced risk for VTE: adjusted conditional odds ratio (OR) 0.45 (95% CI, 0.29-0.70). In this hospital-based case-control study, a preventive role for angiotensin II receptor blockers as regards VTE risk was suggested. More studies are needed in order to further elucidate the biological mechanisms involved.