The leaves of Hymenocardia acida are commonly used in Northern Nigeria alone or in combination with other plant parts to manage sickle cell disease. Phytochemical screening and antisickling studies were carried out. The phytochemical screening revealed the presence of carbohydrates, tannins, flavonoids, saponins, alkaloids, cardiac glycosides, resins, steroids and terpenes. The leaves ethanol extracts at 0.5, 1.0 and 2.0% w/v were observed to reverse sickled human Red Blood Cells (RBC) using microscopic technique. The antisickling activity was found to be dose dependent. The fractions containing flavonoids, saponins and carboxylic acids were found to be responsible for reversal of the sickled RBC. Therefore, the use of the plant by the traditional medical practitioners in the treatment of sickle cell anaemic patients is justified.