In the search for plants that can fight against hypertension, we have initiated an ethnopharmacological survey on the markets of the city of Abidjan in Côte d’Ivoire. The markets of three districts in the city were visited for this purpose: Yopougon, Abobo and adjamé. In yopougon, we visited the Wassakara market. The central market and the Gouro market were respectively chosen for the communes of Abobo and Adjamé. This choice is justified by an impressive number of sellers of medicinal plants in these markets. The survey made it possible to interview 90 herbalists on the basis of a questionnaire sheet. These investigations revealed 21 species of plants used in traditional medicine, in the treatment of hypertension. The modes of administration of these herbal medicines are decocted to drink and pastes to purge. In comparison with the calculated citation frequencies, two plants are very frequent. They are: Nymphaea lotus (Fc = 9.01%) and Phyllantus amarus (Fc = 8.02%). These two plants are found in all the sellers of medicinal plants visited during our surveys. A phytochemical screening was performed to assess the scientific basis for the empirical use of these two most common plants. These tests revealed that these plants contain sterols, polyterpenes, polyphenols, flavonoids, saponosides and alkaloids with a strong presence of flavonoids and alkaloids in the species Nymphaea lotus. The hypotensive effect could be related to the strong presence of alkaloids and flavonoids. These two plants could be of interest scientific world in the fight against hypertension.