Ethnopharmacology can be basically defined as "the interdisciplinary scientific exploration of the biologically active agents that are traditionally employed". Therefore, the ethnopharmacological approach is based on a body of work that spans several disciplines such as botany, chemistry, and pharmacology. This includes field observations, descriptions of the utilization and bioactivities of folk remedies, botanical identification of the plant material as well as phytochemical and pharmacological research. Investigations of the indigenous remedies and their possible effects have attracted attention of many researchers for ages. Drug discovery from natural sources in the light of ethnopharmacological studies has an important role in the development of current therapeutic systems. Plants, animals and minerals are among the natural products that have been the basis in the treatment of many diseases for centuries. Recently, much attention has been paid to pharmacognostical, phytochemical and pharmacological studies of traditional medicinal plants. Moreover, biological activity potential of natural medicines has been investigated in many preclinical and clinical studies, revealing diverse biological effects of a wide range of plant derived compounds in various classes of chemical groups. The majority of the natural sources whose active compounds are currently employed actually has an ethnomedical use. Therefore, recently, many of the pharmaceutical companies have renewed their strategies in the field of natural product research in order to bring out potential sources and new molecules for the drug development. For the discovery and development of novel, safe and affordable medicines, the ethnopharmacological knowledge could be beneficial thanks to its approach that could be supported by experimental base. In the present study, ethnopharmacological aspects of herbal medicine and plant-based drug discovery process will be emphasized and important issues in their use as complementary medicine will be mentioned.