The purpose of the present investigation is to find out the influence of ego-strength and alienation on performance of blue-collar industrial workers. The sample consists of 150 workers of Diesel Locomotive Works, Varanasi (U.P.). The level of performance was assessed on the basis of production records for the last one year (1977-78). Alienation Scale has been used to determine the level of alienation (Dutta & Kureshi, 1975). Ego-strength Scale developed by Q. Hasan has been used to determine ego-strength. The 2 x 2 factorial design has been employed in the present investigation. The results are analysed in terms of mean, standard deviation, critical-ratio, analysis of variance, and correlation. The results indicate that the level of performance of high ego-strength group is significantly higher in comparison to low ego-strength group of workers. The level of performance of less alienated workers is also better in comparison to high alienated workers. A significant negative correlation exists between alienation and performance. Ego-strength and performance are positively correlated. But the partial correlation shows that performance is not significantly affected by ego-strength and alienation rather the level of performance itself affects the ego-strength and alienation and its relationship.