Ethnobotany, as a research field of science, has been widely used for the documentation of indigenous knowledge on the use of plants and for providing an inventory of useful plants from local flora in Asian countries. Plants that are used for traditional herbal medicine in different countries are an important part of these studies. However, in some countries in recent years, ethnobotanical studies have been used for the discovery of new drugs and new drug development. In general, experiences gained from ethnobotanical approaches of traditional medicinal studies in China and Himalayan countries have helped drug production and new drug development. At the same time, in many cases, over-harvesting, degradation of medical plants, and loss of traditional medical knowledge in local communities are common problems in these resource areas. Issues of indigenous knowledge, intellectual property rights, and uncontrolled transboundary trade in medicinal plants occur frequently in the region. This paper discusses ethnobotanical approaches of traditional medicinal studies, in reference to experiences from China and Himalayan countries, with an emphasis on the conservation of traditional medical knowledge and medical plant resources.