The present study aimed at investigating the speed and accuracy of introverts and extravcrts on Choice Reaction Time and Visual Detection Task among 60 university male and female students assigned to meet the requirement of 2 × 2 between group factorial design. On Choice Reaction Time, the performance was assessed in terms of RT and errors committed; and on Visual Detection Task, the indices of performance were the number of digits detected and errors committed. The data were analysed by ANOVA. The findings of the study are at variance with the contentions of Eysenck: 1. introverts performed better than extraverts on Choice Reaction Time in terms of speed; 2. in Visual Detection Task, for the first 9 minutes extraverts maintained superiority as contended by Eysenck, but in the last minute lost the edge and introverts become better though insignificantly. The results on the Choice Reaction Time and last minute performance on Visual Detection Task controverts Eysenck’s original standpoint regarding speed and accuracy in introverts and extraverts.