Tipping is unique in that the customer provides a major portion of the employee’s wage. Because tipping is voluntary and because it usually occurs retrospectively of the service rendered, tipping practices have stimulated historic interest from both economic and psychological perspectives. This research extends the body of knowledge on tipping by integrating recent advances in motivational research which support the existence of a universal, multifaceted model of intrinsic motivation. Inasmuch, the present research investigated the underlying motives for tipping under various conditions of service. Findings supported the existence of six underlying behavioral dimensions associated with tipping: (a) Heuristic Model, (b) Impress Others, (c), Reciprocal Reward, (d) Social Obligation, (e) Generosity, and (f) Control Service. Each of these six corresponded closely with the basic motivators proposed by the multifaceted model. Results from a hierarchical linear regression confirmed the overriding influence of heuristics on tip amounts under various service conditions