Synopsis Diseases are major constraints to the sustainable development of aquaculture industry. Many diseases affecting present day aquaculture is resultant of intensification of culture practices without the basic perception of intricate balance between host, pathogen and environment. Many times disease outbreaks in fish and prawn are closely linked to environmental deterioration and stress associated with intensification of culture practices. Different Stress factors such as inadequate physico-chemical and microbial quality of culture water poor nutritional status and high stocking density can cause infection by opportunistic pathogens. Moreover, unprecedented movement of aquaculture seed and brood stock between regions has made the intrinsic pathogens to activate and produce disease in host and other stressful conditions affecting the native fish stocks. The entitled book “Disease Management in Freshwater Pisciculture” spread over 28 chapters covers the complete picture on fish and prawn disease scenario in the country with particular reference to the latest developments made in the aquatic animal developments made in the aquatic animal health management sector. The detail etiology, clinical signs, prophylaxis and treatment of diseases have been discussed in a simplified manner for easy understanding of researchers, teachers, trainers and students in the field. Since it is not possible to describe the disease in detail, this book will guide to identify and manage the diseases including some aspects of latest developments in fish disease research. A cover all the progressive areas of health management starting from basic status of diseases towards various approaches to diagnose, prevent and control disease condition. Few chapters have also been incorporated to understand the immune system of fish and prawn and also how do they work. The recent approach to prevent or control fish or prawn diseases through immunostimulation has also been included.