The present study aimed to identify the level of occupational stress and the level of mental health and to find out the extent of their relationship with the employees of Oman Telecommunications Company in Muscat Governorate. The study adopted a number of variables for the study sample which were (gender, marital status, scientific qualification, years of experience). In order to achieve the study's objectives, the study uses the descriptive linking approach method, and the occupational stress scale done by Ragheb and Mustafa (2010) and the mental health measure of Abdul Khaliq (2011). The study sample consisted of all employees working in the main building in Oman Telecommunications Company in Muscat Governorate who were (1681), while the study was applied to (504640) employees from various departments and units. In order to answer the study questions, The statistical results were calculated in the arithmetic mean, standard deviations, frequency, T-test, mono-variance analysis, alpha-cronbach, Pearson, Jettmann and Schiffe. The results showed that the occupational stress of the employees of Oman Telecommunications Company had reached a low level, and after the boredom ranked first, while after the deficit became in the last place. Whereas, the levels of mental health in the sample of the study was high,. The results of the study showed that there were no statistically significant differences between occupational stress and mental health according to the following variables (gender, marital status, years of experience, and scientific qualification), while the results of the study showed that there were statistically significant differences in the sample of the study due to marital status. The sample with other social status had statistically significant differences. Finally, the results of the study indicated that there was a statistically significant correlation between the occupational stress and mental health of the study sample at the level of (0.01). The linear correlation coefficient between the occupational stressors and the mental health level was negative and opposite. Mental disability, and post-disability outcomes were significantly correlated with mental health, while the results did not show a correlation between boredom and mental health despite the value of the negative correlation coefficient. The study concluded with a set of recommendations and suggestions for the employers of Oman Telecommunications Company in Muscat.