Background: Justified Death Attitude (JDA) is a new term about one’s agreement with killing someone else. Previous studies have shown the Justified Death Attitude Scale (JDAS) is valid and reliable. We also know that some variables like major and gender are associated with JDA, but we do not know how gender, ethnics, generation, and sanity differently would affect JDA. Objectives: This was a cross-sectional study to evaluate the effect of ethnics, generation, gender, and sanity on the attitude of the people about justified death. Method: In 2022, 744 participants, including 368 male and 376 female participants were selected through convenience sampling method in Tehran, Ilam, Khorramabad, and Sanandaj. Participants were stratified according to age (528 adults, 216 older adults), religion (538 Shiite, 108 Sunni, and 98 Assyrian participants), and sanity status (460 normal and 284 participants with possible mental illness). Participants filled out General Health Questionnnair-12 (GHQ 12) and Justified Death Attitude Scale (JDAS). Results: Older, Shiite, and Sunni participants agreed more with death penalties, but younger and Assyrian participants disagreed more with death penalties. Furthermore, young, Assyrian agreed more often with euthanasia. Different generations think significantly differently about the type and severity of execution and euthanasia. Conclusion: The more diverse the sociocultural background, the more different is the attitude about justified death. That might be due to dissimilar crystallization of sense of self in different socio-cultural backgrounds and through different cognitive processes.