The book 'Advanced pathology and treatment of diseases of poultry' has been prepared to cater to the needs of students of the veterinary colleges, diagnosticians engaged in disease investigation and practicing veterinarians in different states of this country. The syllabi prevalent in different agricultural universities have been kept in view in preparing the manuscript of this book. Sincere efforts have been made to insert all pertinent pathological changes in different poultry diseases with the object of making this book of high value to the students at both undergraduate and postgraduate levels in the veterinary colleges. More and more stress has been laid on the information in relation to signs, gross and microscopic lesions of avian diseases prevalent in poultry flock for their diagnosis.