Plants are by far the most important source of natural therapeutics, and their role in enhancing the longevity and quality of life is gaining prominence in the world and still the plant is often the most neglected part of plant-based medicines.Current problems with medicinal plant products that compromise the quality and safety of medicinal plant products have included contamination with biological and environmental pollutants, adulteration with misidentified species resulting in quantitative and qualitative variations in bioactive compounds. It is, therefore, necessary to standardize and validate the medicinal plants in terms of scientific authentication at bioefficacy levels . In view of the current importance of and interest in herbal drugs, it is target to prepare an International Codex containing the details of plants so that their sale use could be controlled judiciously. Therefore, present book contain antimicrobial, antioxidant and phytochemical screening of certain Indian Medicinal Plants for scientific validation.Authors also acknowledge the Department of Science and Technology, Jaipur for their valuable support for providing financial assistance for research work.