Background and Objectives: Accurate assessment of patients' death depression requires a specific tool that is appropriate to the culture of each community. Therefore, the aim of this study was to evaluate the psychometric properties of the Death Depression Scale in women with breast cancer. Methods: In this methodological study, 246 breast cancer patients presenting to Qazvin Provincial Hospital completed the 17-item Templar Death Depression Scale. Psychometric properties of this scale were evaluated by exploratory and confirmatory factor analysis. Reliability was also assessed using Cronbach's alpha, omega and composite reliability. Results: Exploratory factor analysis showed that six items in the Persian version did not acquire the required loading factor, and were omitted. The remaining eleven items as a single factor accounted for 66. 91% of the variance of this concept. In confirmatory factor analysis, 11 items had appropriate fit indices (χ 2 = 97. 664, p <. 001, χ 2 / df = 2. 504, GFI =. 932, CFI =. 972, IFI =. 973, TLI =. 961, SRMR =. 030, and RMSEA =. 079). A Cronbach's alpha coefficient of 0. 95, Omega coefficient of 0. 95, and composite reliability coefficient of 0. 96 indicated the acceptable reliability of the 11-item version. Conclusion: The results of this study showed that the 11-item Death Depression Scale was valid and reliable in Iranian patients with breast cancer. Given the appropriate psychometric parameters, this scale can be used to assess death depression in future studies.