For the purpose of promotion of mental health in the rural elderly, the author surveyed 558 elderlies aged 60 years or more, and assessed the prevalence rates of depression and cognitive impairment by using self-rating depression scale of Zung (SDS) and the Korean version of mini-mental state examination (MMSEK). Also the association between depression or cognitive function and socio-environmental factors were investigated. The major findings were as follows ; 1. The prevalence rates of severe depression and cognitive impairment were 20.9% and 14.9% in all the elderly of both sexes, respectively. 2. The rates of depression and cognitive impairment increased with increasing age in both sex groups. The mean scores of SDS increased and the mean scores of MMSEK decreased significantly among them (p<0.01). 3. Those being female, widows or widowers, and those having low levels of physical activity, showed significantly high the mean scores of depression and had significantly low the mean scores of cognitive impairment (p<0.01). 4. The depression scores relating to decreased libido, confusion, psychomotor retardation, hopelessness and indecisiveness were relatively high in both sexes. 5. All the items of mini-mental state examination were significantly correlated with depression. 6. In stepwise multiple regression analysis on depression, MMSEK, level of physical activity, chronic disease, marital status and family income were selected as highly correlated variables, and the $R^2$-value for these variables was 33.7%. 7. In stepwise multiple regression analysis on cognitive function, level of physical activity, age, depression, sex and marital status were selected as highly correlated variables, and the $R^2$-value for these variables was 62.6%. The depression and cognitive impairment of the elderly were positively correlated with nearly all sociodemographic variables.