The aim of this work was to study the antihypertensive activity of the hydroalcoholic extract of the aerial part of Lycpodium cernuum in rats made experimentally hypertensive with a hypersodic diet. Its hypotensive effect was studied in vivo and its vascular effect was studied in vitro on the isolated aorta. The normal blood pressure of the rats was 103.83 ± 3.7 / 82.13 ± 2 mmHg (systole/diastole). After 21 days on the high-salt diet, their blood pressure rose to 208 ± 2.2 / 150.06 ± 2.5 mmHg. This pressure returned to normal after 22 days in the control lot compared to 6, 10 and 16 days in the animals treated with the extract at 400, 200 and 100 mg/kg of the extract orally administered. In vitro, the extract relaxes the isolated aorta contracted with norepinephrine 10-3 M with an EC50 equal to 0.65 ± 0.02 mg/ml. These results show that Lycopodium cernuum extract has an antihypertensive activity in rats by its vasodilatory effect. This activity could be due to the presence of phenolic compounds and/or alkaloids in the extract.