Dissertation (Master in Business Administration)Studies which link job satisfaction and workers’ performance often, provide inconsistent findings. Due to that, researchers directed this as an area that required more attention. This study, was out to investigate the impact of job satisfaction on workers’ performance by taking a case of Tanzania Electric Supply Company Limited (TANESCO), Dodoma Municipality. The work was carried out by using a case study methodology and employed multiple methods in data collection and analysis. It involved both the top management of the firm and ordinary employees. It was found out that, there were mainly five factors which triggered workers to become satisfied with their jobs, namely; good working environment, good communication flow, good managerial system, an attractive package of salary, and job security. Contrary to this, there were factors which caused some dissatisfaction to some workers. These were; poor working relationship with their seniors, long stay at the firm without promotions, lack of training opportunities, and uneven provision of incentives to employees. Further, the study established a weak relationship between job satisfaction and workers’ performance. However, the findings were found to be consistent with various literature surrounding job satisfaction and workers’ performance studies. Moreover, findings established that the satisfaction level of the workers at TANESCO was invariably high. It was recommended that the management capitalized on those factors which made employees happy with their jobs, in order to sustain job satisfaction for the betterment of the employees, customers and the firm at large. It was also recommended to the management, to see factors that caused dissatisfaction as an eye-opener for it to reflect and work on the factors, so as to make all of their employees as happy as possible. Finally, employees of TANESCO were advised to reciprocate by providing quality services to customers, in order to enable their firm to excel.