In contingency judgment tasks (CJT) people typically overestimate their control over an outcome. We hypothesized that this outcome density effect (a type of illusion of control) may be due to an attentional bias toward positive outcomes, which may lead one to ignore negative outcomes and thus to underestimate their occurrence. In order to directly test this hypothesis, we manipulated the outcome’s salience in a CJT, inducing participants to focus on either positive or negative outcomes. Results showed that enhancing the salience of positive outcomes (wins) enhanced participant’s judgment of control more so than enhancing than of negative outcomes (losses). Moreover, when positive outcomes were salient, participants overestimated the amount of money they had earned during the experiment. In sum, the salience of the “outcome event” affected both judgment of control and memory for positive, more than for negative events, implying that attentional mechanisms may play an important the role in the illusion of control phenomenon.