Beta-glucans are the polysaccharides obtained from the cell wall of fungi, yeast, bacteria, and cereals with different physicochemical properties depending on the source. Beta-glucans are polymers with β-1,3 glucose as core linear structure and vary with respect to side branching, solubility, viscosity, gelation properties, and molecular weight. They are well known as cell response modifiers with immune-modulating, nutraceutical, and health beneficial effects, including anticancer and pro-apoptotic properties. This book is the first of its kind, focusing on the different sources and properties of beta-glucans. The unique features of this book will be the focus on the extraction method of beta-glucans, chemistry, stability, modification, and health benefits of beta-glucans. This book is suitable for students, scientists, and professionals in food science, food processing, product development, nutrition, and other health sciences. This book will be typical in its form, and we hope that it will represent an example for future works in this and related areas. We aimed to summarize and review the outcomes and knowledge gained so far in the said area.