The present study investigated the influence of the Type A coronary-prone behavior pattern on attribution processes. Given the exaggerated achievement striving and competitiveness of Type A's, it was predicted that these individuals would be more motivated to succeed in a prisoner's dilemma game than would Type B's. Increased motivation to succeed was predicted to lead Type A's to exaggerate the amount of dispositional information they would believe they had inferred from observing the behavior of a future opponent, since such a belief would lead to increased confidence about predicting the target's behavior and thus increase subjects' perceived control over the outcome. Results supported the predictions when the hard-driving competitiveness dimension of the Type A pattern was used as the individual difference variable. Moreover, evaluations of future opponents in the prisoner's dilemma game also differed as a function of the hard-driving competitive dimension. Results are discussed in terms of a person by situation interactive model of motivational influences on attribution processes, and in terms of potential interpersonal effects of the cognitive behavior of Type A individuals.