Ever since the dawn of civilization, the ambient vegetation and the resources constituted major source of human existence for various substantial requirements. Our present knowledge on plant resources emerged from the traditional heritable knowledge descended from generation to generation. However, traditional knowledge pertaining to several aspects remained untapped from various remote localities or populations. Furthermore, with the present trends of excessive exploitation of natural resources and degradation of habitats, conservation and ecological management require coherence of traditional skills and modern approaches. Therefore, the present study is to record traditional plant based knowledge among the inhabitants of Siwalik region of Uttarakhand Himalaya. Extensive field survey was made for the collection of data on the medicinal aspects of plant species in the study area covering the parts of districts Pauri, Dehradun and Haridwar. During the course of study 130 plant species belonging to 65 families are reported, used as traditional medicine by the local inhabitants of this region.