Objective: Nowadays stress and tensions are among the most important factors affecting health. Identifying the stressors and their determinants provides substantial information for understanding the health of the community. Method: This descriptive cross-sectional study was conducted on citizens over 18 years who were living in all 22 districts of Tehran in 2017. The participants were selected using multistage cluster sampling method. The research tool was a checklist that evaluated various factors. Different statistical tests, such as descriptive tests and logistic regression, were used for data analysis. Results: Of the participants, 82. 7% experienced at least 1severe stress during the past year. In the last year, 45. 6% of the participants had at least 1severe economic stress, 32. 3% had at least 1severe family-related stress, 28. 8% had at least 1severe health-related stress, and 25. 7% experienced at least 1severe future-related stress. The most common psychosocial stressors experienced in the last year were concerns about personal/family future (53. 7%), concerns about the financial and economic future (47. 1%), and the high cost of living (41. 7%). However, the most severe stresses were due to the participants’ concerns about family health (14. 4%), personal/family futures (13. 2%), and financial and economic future (12. 7%). Furthermore, health status, subjective socio-economic status, and age were the most important predictors of severe stress experiences. Conclusion: It is necessary to take actions to reduce the prevalence of common severe stresses. In addition, psychologists, psychiatrists, counselors, and social workers need to provide stress management interventions carefully to their patients.