Introduction: This research aims to determine the mental health status of population aged 15 and over in the province of Bushehr in 2015. Methods: The statistical population of this cross-sectional field survey consisted of residents of urban and rural areas of Bushehr province in Iran. Through systematic random cluster sampling, 1200 individuals were selected from the residents of urban and rural areas of Bushehr, Deilam and Borazjan. The 28-item version of the General Health Questionnaire was applied as the screening tool. Data were analyzed using SPSS, version 18.0 for windows. Results: The results of this study showed that using the traditional scoring method, 23.4% of the subjects (29% of females and 14.7% of males) were suspected of mental disorders. The prevalence of suspected psychiatric disorders in rural areas (24.5%) was more than the prevalence of these disorders in urban areas (22.8%). The prevalence of suspected anxiety and the somatization of symptoms was higher than the prevalence of social dysfunction and depression, and the prevalence of these components was higher in women than men. The findings of this study also showed that the prevalence of suspected cases of mental disorders increased significantly with age. The prevalence of suspected cases of these disorders was higher among females, the age group of 65 and older, people living in rural areas, divorced and widowed, students and primary and secondary education than other groups. Conclusion: The results of this study show that more than one fourth of the sample were suspected of mental disorders, and the prevalence of these disorders has increased from 21.3% in 1999 to 23.4% in 2015. Therefore, it seems necessary for the provincial public health authorities to take the needed steps for providing requirements encompassing prevention and promotion of mental health in this are