This book contains consolidated information on the current status of Fusarium wilt disease of guava in India and abroad. The fungal pathogen Fusarium causes vascular wilt diseases in many economically important plants resulting in huge losses viz.; death of plants and fruit production. The fungus is taxonomically complex and consists of many pathogenic forms that are morphologically similar. The most important pathogenic forms are F. oxysporum f. sp. psidii (Fop) and F. solani (Fs), the causal agent of Fusarium wilt of guava. The results presented hereon by the authors are a compilation of recent findings on the cultural, morpholological, physiological, pathological, molecular and phylogenetic characteristics of these species. This will allow us to understand the biology of these pathogens which in turn will lead to an effective control strategy for Fusarium diseases. This will additionally increase the understanding of these diseases, potentially improving crop productivity. The research data presented here can be explored in terms of developing integrated strategies for disease management. Furthermore, it may help researchers in the specific field of agri-biotechnology to develop a genetic map of Fusarium spp. isolates of guava.