Purpose—To evaluate the efficacy and safety of intravenous hidralazine in arterial hypertension. Patients and Methods—12 patients, meanage 45,33 15,82,8 men and 4 women all of them with systolic (S) arterialpressure (AP) 180 and or diastolic (D) 126 mmHg with symptoms like headache, incaracteristic toraxic pain and others but without an hypertensive emergency neither acute manifestation of hypertensive encephalopathy through fundi examination were studied. The AP was taked 10 minutes after rest (inicial) and 5, 15, 30 and 60 min (final) after intravenous administration of hidralazine-HCL (5mg) which was repeated when at least 20% AP reduction was not achieved. Results— The inicial and final SAP, DAPand heart rate (HR) wre 208 ± 19,4 and 176 ± 17,2 (p < 0.0001), 133 ± 11,3 and 112 ± 11,5 (p< 0.001) and 72 ± 12,9 and 80 ± 15,5 (NS), respectively. Side effects related to the drug were observed in 3 (25%) patients. One had symptomatic ortostatic hypotension, the second had precordial pain with ST-T changes compatible with myocardial ischemia and the third presented a torax and abdominal cutaneous erithema, but all of them reversible. Conclusion— Intravenous hydralazineHC1 is an alternative when rapid arterial pressurereduction is needed