Organisational Behaviour attempts to examine the individual and group behaviour to describe, understand, predict and control it in organisational settings. At the individual level, OB focuses on perception, motivation and personality driven performance. But the group level behaviour analysis focuses on group dynamics, norms and leadership. It is an Applied Behavioural Science that helps to correct and modify the behaviours in an organisation in accordance with the changes in the environment. This textbook on Organisational Behaviour throws light on the fundamental concepts of OB. It also focuses on important organisational issues such as Personality, Leadership, Motivation and Group Dynamics. With hearty congratulations to all the students who have been admitted to the Four-Year Degree Programme, we present to you this textbook on Organizational Behaviour. This textbook has been prepared strictly in accordance with the Four-Year BBA (Honours) Second Semester Syllabus of the Mahatma Gandhi University and we are sure that it will be a good companion for you in learning this course. We are very much delighted to receive valuable suggestions and criticisms of teachers and students who peruse this textbook. Wish you all success. We bow down before the ALMIGHTY for the unwavering grace, guidance and blessings bestowed upon me for materializing this academic endeavor.