This book presents current aspects associated with pollen allergy, a significant medical complication which is still under extensive research. The information encompassed in this book will be of considerable importance to those interested to gain knowledge regarding molecular basis of pollen allergy, like cross-reactivity between pollen and pollen-plant food derived allergens, allergen proteins polymorphism and its implications in allergic disease, and techniques for clinical trial and future research. The book also illustrates insights regarding the application of molecular tools in allergens identification and quantification like multiplex methodologies, assisting in the advancement of the standardization procedure of pollen protein extracts, assuring efficacy and security in allergy diagnosis and immunotherapy, and also explores the environmental factors, and alternative efficient anti-allergic and preventative techniques for allergic diseases.