Pharmacognostic studies of Diodia scandens Sw (Rubiaceae) were carried out. Diodia scandens Sw is a straggling herb with a taproot, slender stem and compound leaves used for treatment of various diseases such as dysentery, diarrhea, asthma, convulsion, epilepsy, oedema, gout, swelling and it is said to be anti-abortifacient, antidotes, antimicrobial, anti-inflammatory in Nigeria and other countries. The phytochemical screening of the leaf extract revealed the presence of saponins, tannins, cardiac glycosides and absence of flavonoids, phlobatannins, alkaloids and anthraquinones. Anatomical examination has revealed the occurrence of paracytic, anisocytic, diacytic and brachyparacytic on the abaxial surface ad only few paracytic on the adaxial surface. The stem showed druses of crystals. There are four different types of abnormal stomata which are vertical contiguous stomata, two stomata sharing one subsidiary cell, a stoma with unopened stomatal pore and a stomata with one guard cell. The surface of the epidermal anticlinical cell walls, guard cell area, stomata index, presence or absence of trichomes and venation characters can be used as a great diagnostic tool with a view of preparing a monograph.