Rewards have been shown to impair performance of a reinforced behavior. The work surrounding these detrimental effects of rewards has not been met with unanimous support. Does this phenomenon described in Deci's Cognitive Evaluation Theory concerning the detrimental effects of reward exist? Is Deci's Cognitive Evaluation Theory adequate to explain this phenomenon? A meta-analysis was employed to determine the existence of the detrimental effects of extrinsic rewards on intrinsic motivation. Results from this analysis showed that within strictly defined parameters the phenomenon defined by Deci exists. Implications from this analysis exemplify researchers' need for closer supervision of the operationalization of variables based on the theoretical framework.