This book is about organizational citizenship behaviour in human service organizations. Organizational citizenship behavior is a relatively new construct that has generated interest not only among the researchers but also policy makers, and it is considered to be a strong predictor of organizational effectiveness. One of the main objectives of this book is to explain organizational citizenship behaviour from a psychometric viewpoint, in context of human service organizations. Considering the recommendations put forth by various authors of books written on organizational citizenship behaviour, there is an urgent need for a book that explains organizational citizenship behaviour from the perspective of human service organizations. It is hoped that the book will serve as a foundational resource for researchers working for the welfare of human service organizations, especially those functioning in the Asian region.