The study investigates different factors influencing people to have more stress in a hydropower unit located in city of Esfahan, Iran. Since there were only 81 people working for customer service section of this company and the proposed study tries to focus only on this part of the firm we have decided to distribute questionnaires among all of them. The questionnaire consists of two parts, in the first part, we gather all private information such as age, gender, education, job experience, etc. through seven important questions. In the second part of the survey, there are 66 questions, which include all the important factors influencing employees & apos; stress. Cronbach alpha is calculated as 0.946, which is well above the minimum acceptable level. The results of our ANOVA tests shows that among different factors, difficulty of working condition as well as work pressure are two most important factors increasing stress among employees. The other findings indicate that there is not a significant difference on work stress among different groups of employees in terms of their job title, educational level, employment type and gender (P & GT; 0.05). The other finding indicates that there is a meaningful difference between different groups of people with various ages, marital status and job experience (P & GT; 0.05).