This book comprehensively covers critically investigated information on medicinal plants prioritized for their anti-allergy properties. It offers insights into strategies related to the distribution, mechanism of action, and assessment of antiallergic medicinal plants, and also delves into crucial aspects of modern biotechnological tools, addressing their implementation challenges, presenting innovative approaches through case studies, and exploring opportunities for nanotechnologies. These elaborated discussions aim to raise awareness and bridge the gap between human health and the biodiversity of antiallergic medicinal plants. As the book navigates the uncertainties of plant-based medicines in the post-COVID-19 era, it provides real-world applications showcasing the specific utility of medicinal plants through advanced biotechnological insights. This book covers several medicinal plants associated with antiallergy, exploring their modes of action, available secondary metabolites,and estimation methods. It also emphasizes all modern biotechnological interventions aimed at propagating, multiplying, and conserving this unique treasure trove of medicinal plants. The World Health Organization estimated that 80% of the populations of developing countries rely on traditional medicines, mostly plant drugs, for their primary health care needs. Increasing demand in both developing and developed countries resulted in the expanding trade of medicinal plants and has serious implications for the survival of several plant species, with many under threat of becoming extinct. This book describes various approaches to conserving these genetic resources. It discusses the whole spectrum of biotechnological tools from micro-propagation for large-scale multiplication and cell-culture techniques to the biosynthesis and enhancement of pharmaceutical compounds in plants. It also discusses the genetic transformation as well as short- to long-term conservation of plant genetic resources via synthetic seed production and cryopreservation, respectively. This reference book is useful for researchers in the pharmaceutical and biotechnological industries, medicinal chemists, biochemists, botanists, molecular biologists, academicians, students as well as allergic patients, traditional medicine practitioners, scientists in medicinal and aromatic plants, and other traditional medical practitioners.