The purpose of the present study is to find out the relationship between job satisfaction, ego-strength and job performance. The S-D Employees Inventory has been administered as measure of the workers' satisfaction. To assess ego-strength the Hasan's E-S Scale has been applied. The amount of production has been obtained from the daily work records from August, 1977 to January, 1978. The study was conducted at Uttar Pradesh State Spinning Mills Co. (No. 1), Barabanki (U.P.), India. Results are analysed in terms of mean, standard deviation, critical-ratio, F-ratio and coefficients of correlation. The findings indicate that the level of job performance is significantly higher in highly satisfied group in comparison to low satisfied group. A significant difference in performance was also observed between high and low ego-strength groups. Significant positive relationships between job satisfaction and ego-strength, job satisfaction and job performance as well as ego-strength and job performance have been established.