The first chapter describes an introduction to medicinal plants and their use in traditional system of medicine, current status of medicinal plants and natural products isolated thereof and isolation of phytochemicals/bioactive molecules from these plants which act as therapeutic agents. The second chapter includes the review of literature of ethno-pharmacology, chemistry and pharmacology of genus Rhododendron. The third chapter highlights the phytochemical investigation of Rhododendron lepidotum. Overall four natural compounds were isolated which were characterized and identified on the basis of physical properties, spectroscopic data analysis and chemical derivatisation. Out of four isolates two compounds were found as new molecules.