Objectives  Aging is a biological process, experienced by all living things, including humans. The most important factor in this period is the death anxiety. This study aimed to determine death anxiety and its relationship with social support and adherence to religion in unmarried and married men and women.
Methods & Materials In this study, causal-comparative and correlation methods were used. The study was conducted on 376 people; 190 men and 186 women (married and unmarried). The participants were selected from high school graduates from districts 2, 3, 5, 6, and 22. They were 60 and 75 years, and selected by using convenience sampling. Death anxiety scales 27-item form, 19-item form for social support questionnaire and 26-item form for religious attitudes were used to measure study variables. Data were analyzed by 1-way ANOVA and the Pearson tests using the SPSS 21.
Results The results of correlation analysis indicated significant and direct relationship between social support and the fear of dying (P <0.05) and fear of death by others (P <0.05), as well as with the overall death anxiety (P <0.01). With regard to the relationship between adherence to religion and death anxiety components, only the relationship between faith and fear of the consequences of dying was significant (P <0.01). The analysis of variance indicated a significant difference between unmarried and married men with regard to death anxiety. Unmarried men experienced more death anxiety (P <0.01). The average death anxiety scores among women was more than that among men (P <0.01), but there was no significant difference between unmarried and married women with regard to death anxiety. 
Conclusion Increased social interaction, adherence to religion and marriage can decrease death anxiety and improve the mental health of the elderly, especially elderly women.