Background: One of the effective factors in the healthy living of the elderly is health-promoting behaviors. Objectives: This study aimed to investigate the relationship between health-promoting behaviors and mental health in elderly military veterans in Iran. Methods: Using available sampling method, this descriptive-analytical study was performed on 280 elderly military veterans over 60 years old referred to a military health center in Urmia, Iran. We used a questionnaire comprising three sections as follows: (1) elderly demographic information; (2) health promoting behaviors; and (3) mental health assessment. The collected data were entered into SPSS software v.20 and analyzed by chi-square and Fisher’s exact tests. Results: The results showed that among the health-promoting behaviors, non-consumption of alcohol, controlling blood pressure, and not smoking had the highest frequency, and the injection of influenza vaccine had the lowest frequency. The relationship between health-promoting behaviors and the level of mental health showed that smoking, stress, alcohol consumption, and not exercising had a significant relationship with anxiety and stress (P < 0.05). Also, the individuals who consumed more fruits and vegetables had less stress than those who consume lower amounts of these foods (P < 0.05). Also, people who consumed low-salt, low-fat, and dairy-based foods, controlled their blood pressure regularly and had received the flu vaccine had a better mental health. Conclusions: According to the results, a special attention should be paid to these factors in planning to teach health-promoting behaviors to improve health and counseling services in the elderly.