This book is written for undergraduates keeping in view their special requirements and their dire need of a small book on Psychiatry. The main object of this book is to introduce the students with the elementary knowledge of Psychiatry and enable them to prepare for examination. It may also be useful for trainee doctors who opt to work in Psychiatric hospitals. It is not meant to replace the standard textbook of Psychiatry. Its topics have been carefully selected to include only those aspects, which are either not touched upon or discussed in detail. this has greatly helped me to limit the volume of this book. Valuable suggestions and criticism will be greatly appreciated to this end.