Antiplatelet therapy (AT) is indicated in hypertensive patients with increased cardiovascular risk. The literature about the adequate or inadequate prescription of AT is scarce. We conducted a prospective descriptive study to quantify therapeutic inertia and nonguideline-recommended prescription (NGRP) of AT (aspirinor clopidogrel or both), and to assess associated factors, calculating the adjusted odds ratios (ORs) from multivariate models. In 2007-2009, 712 primary health-care hypertensive patients in a Spanish region were enrolled. Inertia was defined as the lack of an AT prescription, despite being indicated by guidelines, whereas NGRP was defined as AT prescription when there was no guideline recommendation. We also recorded cardiovascular variables. Inertia and NGRP were quantified for primary and secondary prevention. Of 108 patients in secondary prevention, 53 had inertia (49.1%, 95% confidence interval (CI): 39.6-58.5%). Associated profile: female (OR=0.460, P=0.091), no dyslipidemia (OR=0.393, P=0.048), no coronary heart disease (OR=0.215, P=0.001) and high diastolic blood pressure (OR=1.076, P=0.016). In primary prevention, NGRP was present in 69 of 595 patients (11.6%, 95% CI: 9.0-14.2%). Associated profile: male (OR=1.610, P=0.089), smoking (OR=2.055, P=0.045), dyslipidemia (OR=3.227, P<0.001) and diabetes (OR=2.795, P<0.001). Although certain factors were clearly associated with these phenomena much still remains to be learnt.