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.