The effect of outcome and type of attribution on self-efficacy was investigated in an experiment involving cognitive task. The participants (20 males and 20 females) were put to pre-test (before performance feedback and attribution) and post-test (after receiving performance feedback and attribution). The study involved a 2X2 factorial design with two type of outcome (success/failure) and two types of attribution (ability/effort) with 10 subjects (5 males and 5 females) in each cell. The results of the experiment revealed that the subjects widely differed in their judgments of self efficacy under pre-test and post-test conditions. It was found that success outcome had influenced the self-percepts of efficacy. The nature of attributions also showed influenced on these judgments. The group did not differ in terms of actual performance on the given task.