Objective: To recognize and screen common mental disorders in elderlies and determine their relationship with social support in Shiraz, Iran. Methods: In this cross-sectional analytical study, 400 elderlies aged >60 years from Shiraz were selected through stratified random sampling. Data collection was done by 3 demographic data, Medical Outcome Study (MOS), social suppor t, and standardization of mental disorders symptoms checklist 90 (SCL-90) questionnaires. The collected data were analyzed with SPSS 22, using descriptive statistics, Pearson correlation coefficient, and univariate and multivariate linear regression analyses. A P value <0.05 was regarded as statistically significant. Results: A total of 400 elderlies (mean age = 67.39 ± 6.89), among whom 204 individuals were female (51％), participated in the study. Somatization and phobic anxiety were the most (68.9％) and least (14.2％) prevalent disorders, respectively. The average total score of social support was 85.59 + 3.5. Social support and its 5 subscales showed statistically significant negative correlation with SCL-90 total scores and its 9 domains (P < 0.05). A 1-point increase in social suppor t score results in reduction in the psychological disorders score by 0.35 point (P < 0.001). Conclusions: It seems necessary to plan and make policies by the authorities to increase social support and reduce the burden of common mental disorders in the elderly.