The findings of presented in this book provide useful information for the industry and practitioners in Iran. For Iranian organizations that desire to improve their employees contribution on OCB, the human resource departments of the companies are recommended to take serious views of humor and communication satisfaction that clearly contribute to employees OCB.The book examines the relationship of two dimensions of humor (that are, how effectively it is used and how often it is used); three dimensions of communication satisfaction (that are interpersonal, group and organizational dimensions); and lastly, five dimensions of OCB (namely courtesy, sportsmanship, civic virtue, altruism, and conscientiousness). The results showed that humor partially predicts communication satisfaction while the relationship between communication satisfaction and OCB was fully supported. The interesting point is that this book has revealed humor would predict communication satisfaction if humor is used effectively.