Trichoderma spp. are biotechnologically significant fungi, being widely used both in agriculture and industry. These microbes are also a potential drug source of clinical importance. In recent years, driven by advances in genetics and genomics, research on these fungi have opened new avenues for its varied applications. Divided into three sections, covering taxonomy and physiology, interactions with plants and applications and significance, this book also discusses topics that have seen rapid developments in the recent years. Various aspects of Trichoderma like molecular taxonomy, sexual and asexual developments, secondary metabolism, beneficial interactions with plants, applications as cell factories and harmful interactions with humans are discussed. This book, thus, hopes to be an essential ready reference for researchers, students and people form industry as well.