Cassia sieberiana is a tree of 8 to 10 meters in height, used to treat various diseases including malaria, dysmenorrhea and many others. Our objective is the scientific valorisation of Cassia sieberiana, a plant used in therapy in Ivory Coast, by evaluating the anti-inflammatory activity of the bark of the root of Cassia sieberiana. To do this, the phytochemical study was carried out in order to determine the main chemical constituents with therapeutic potential, then the acute toxicity by gavage and intraperitoneal injection were carried out and finally the anti-inflammatory activity was verified. The phytochemical study revealed the presence of sterols, polyterpenes, polyphenols, flavonoids, catechic tannins, saponosides and alkaloids. As for the toxicity study, it allowed us to determine by per os route an LD50 > 5000 mg/kg PC, and by IP an LD50 = 524, 807 mg/kg PC graphically and by calculation an LD50 = 400 mg/kg PC. The anti-inflammatory activity of the aqueous extract of Cassia sieberiana at a dose of 200 mg/kg CP is higher than that of diclofenac at a dose of 10 mg/kg CP from the 3rd to the 6th hour of the experiment. Cassia sieberiana is non-toxic by oral administration but toxic by intraperitoneal injection. Cassia sieberiana also has anti-inflammatory activity.