Objective:To present a detailed pharmacognostic study of the leaf of Cayratia trifolia(C.trifolia)Linn.(Vitaceae),an important plant in the Indian system of medicine.Methods:The macroscopy,microscopy,physiochemical analysis,preliminary testing,fluorescence analysis of powder of the plant and other WHO recommended methods for standardization were investigated.Results:Leaves are trifoliolated with petioles(2-3 cm)long.Leaflets are ovate to oblong-ovate,(2-8 cm)long,(1.5-5 cm)wide,pointed at the tip.The leaf surface shows the anisocytic type stomata covered with guard cells followed by epidermis layer.Leaf surface contents including veins.vein islet and vein termination were also determined.Transverse section of leaf shows the epidermis layer followed by cuticle layer and vascular bandies(xylem and phloem).The mesophyll is differentiated into palisade and spongy parenchyma.Abundant covering trichomes emerge from the upper epidermis.Trichomes are uniseriate and multicellular.Strips of collenchyma are present below and upper layer of epidermis.Conclusions:It can be concluded that the pharmacognostic profile of the C.trifolia is helpful in developing standards for quality,purity and sample identification. Objective: To present a detailed pharmacognostic study of the leaf of Cayratia trifolia (C.trifolia Linn. (Vitaceae), an important plant in the Indian system of medicine. Methods: The macroscopy, microscopy, physiochemical analysis, preliminary testing, fluorescence analysis of powder of the plant and other WHO recommended methods for standardization were investigated. Results: Leaves are trifoliolated with petioles (2-3 cm) long. Leaflets are ovate to oblong-ovate, (2-8 cm) long, (1.5-5 cm) wide, pointed at the tip. The leaf surface shows the anisocytic type stomata covered with guard cells followed by epidermis layer. Leaf surface contents including veins. vein islet and vein termination were also determined. Transmission section of leaf shows the epidermis layer followed by cuticle layer and vascular bandies (xylem and phloem). The mesophyll is differentiated into palisade and spongy parenchyma. Abundant covering trichomes emerge from the upper epidermis .richs are uniseriate and multicellular.Strips of coll enchyma are present below and upper layer of epidermis.Conclusions: It can be concluded that the pharmacognostic profile of the C. triolia is helpful in developing standards for quality, purity and sample identification.