The phenomenon of population aging has started in Iran and now, around 10% of the population has 60 years and over; it has been expected that this trend is continued and even accelerated during next few decades. Iran, as a less developed country, has taken some steps to respond to the challenges that aging population would bring to the community, but there are more steps that must be taken in the future. The aim of this chapter is to draw a picture of the present situation and the social determinants of mental health of the older adults in Iran and, also, to describe the existing mental health care systems with a look into the future. This chapter will include the trend of aging population in Iran, the demographics, and social characteristics of the present generation of older adults, social support and welfare systems, agism, elder abuse and mistreatment, epidemiology of mental health problems in older adults, mental health services, education and research in gerontology and geriatric mental health, and national and international cooperation to promote mental health of Iranian older adults.