Fungal world embodies diversified groups which colonize, multiply and survive in nature on many macro- and micro-ecological niches and substrates. Fungi are eukaryotic, achlorophyllous, filamentous or unicellular living organisms which are ubiquitous and cosmopolitan in distribution. Of the estimated 1.5 million fungal species, more than 98,000 fungal species have been described. Approximately 28,000 fungal species are reported from India. The fungi play an important role in biodegradation, recycling of organic matter, pharmaceutical industries, agriculture, medicine, industry, bioremediation, waste management and other activities. In India hardly we have database but for few a books on Indian fungi, compiled from time to time by some mycologists. The present book includes 16 chapters contributed by eminent mycologists. Chapters include data on diversity, taxonomy, ecology and application of Helicosporous fungi, genus Spegazzinia, Rusts and Smuts, Chaetomiaceae, Macrophomina, Rhizoctonia, Russula, wild edible fungi, poisonous mushrooms, insect fungi and other related aspects. This book will be very useful and a valuable addition to the existing literature on the same subject.