Since past few decades because of changing demand for white meat from red meat, the small poultry farms and backyard poultry units developed to commercial farms. The adaptation of intensive poultry keeping methods and rearing of different species of poultry together has given rise to many disease problems. Since the inception of intensive poultry production worldwide farmers were struggling with severe diseases and huge economic losses in their unit. In order to keep pace with ever expanding poultry industry and meeting the increased demand for poultry products, knowledge for prevention and control of poultry diseases will be crucial. The book will enable veterinary students to have sound understanding and working knowledge of poultry diseases. The book will also assist personnel at the poultry disease diagnostic laboratories and progressive farmers. The book devotes total seven sections including basics about avian, bacterial diseases, viral diseases, fungal diseases, parasitic diseases, nutritional deficiency diseases and miscellaneous disorders affecting poultry. There are total 74 chapters in a capsule form. Emphasis has been put on etiology, transmission, epizootiology, clinical signs, gross and microscopic lesions, diagnosis, treatment and control. Where necessary, mention has been made on zoonoses. Necessary images and tables have been added to enhance the understanding of the diseases.