Motivation is a psychic force that derives an individual towards goal realization. Motivation is an encouragement people to do more work. It is basically the process in which behavior is initiated, guided and maintains goal-oriented behaviors. The behavior of people varies from situation to situation and to understand the same, there are various theories of motivation. Theory is basically an idea or assumptions that tries to provide a rationale explanation of cause-and-effect relationships. Various theories have been propounded to make an attempt to know the relationship between motivation and employee performance. Theories and their implications are discussed in this article are : Maslow’s Need Hierarchy Theory, McGregor’s X and Y theory, Herzberg’s Two Factor Theory, Mc Clelland’s Three Need Theory, Victor Vroom’s Expectancy Theory, Adams Equity Theory, Alderfer’s ERG Theory.