Okoubaka aubrevillei is an indigenous and sacred tropical tree in Africa. It is rare with allelopathic properties and has relatively little information available in terms of what is responsible for its usage for medicinal and traditional usage. The phytochemical screening and quantitative analysis of the compounds in the barks and leaves of Okoubaka aubrevillei was determined to ascertain and establish its earlier claimed usage as traditional and modern medicine. The most important classes of secondary metabolites (phytochemical compounds) specifically alkaloids, flavonoids, tannins, saponins, anthraquinnes, mucilages, oses, holosides, coumarin and glycosides were detected in both, the leaves and barks of the tree. Quantitative determination of the phytochemical compounds found in the barks and leaves of the tree revealed that the leaves of O. aubreville tree had significantly higher values of alkaloids, flavonoids and glycosides than barks. Saponins and anthraquinnes were found to be significantly more in barks than in leaves. However, there was no significant difference found in the values of tannins, mucilages, oses and holosides and coumarin in barks and leaves of O. aubreville trees.