Introduction: One of the important events of old age is retirement. Retirement and aging are often interrelated phenomena that appear in a timed symmetry with each other. One of the important challenges in the retirement age is discussing about life quality. Due to lack of relevant researches in Iran, the purpose of this paper is the role of demographic variables and mental health in life quality of military retirees forces.Methods: The studied population, included retired staff in all provinces of the country and sample group consisting of 5265 retired employees selected by cluster sampling. Tools used in this research were" The Life Quality Questionnaire", General Health Questionnaire" and "self-made questionnaire" containing demographic information and correlation was calculated using SPSS 22 software.Results: The results of multivariate regression model showed that the effect of mental and demographic health variables (age, education, economic situation and employment situation), on the quality of life is significant and meaningful, statistically (p<01.0). Also, the effect of demographic variables (gender) on the quality of life isn't significant, statistically (p<05.0).Conclusion: Mental and demographic health variables, (age, education, economic situation and employment situation), have positive correlation with quality of life and people with mental health have higher quality of life, Compared to others.