To determine the prevalence of poor mental health and associated factors in older adults of the Social Enterprise of the State (ESE) Metrosalud.Cross-sectional study using two-stage sampling in hospital units and health centers in the network of the ESE Metrosalud of Medellin. Participants included 342 adults aged 65 and over (57.8% women).poor mental health (measured with the GHQ12), social support (Duke-11); sociodemographic: age, sex, socioeconomic status, educational level, place of residence, marital status and occupation. Study variables were described, the overall prevalence was calculated according to sociodemographic variables. The association of poor mental health with selected variables was estimated by calculating odds ratios with 95% confidence intervals adjusted for possible confounding variables using logistic regression.The senior population without education in both sexes (ORa = 7.61; 95% CI: 2.49 to 23.34), widows (ORa 2.78; 95% CI: 1.21 to 6.40) and men and women with low social support (ORa 3.05; 95% CI: 1.65- 5.66), reported increased risk of poor mental health, compared to their counterparts of reference.We found a high prevalence of poor mental health in the population studied, with differences according to socio-demographic factors, suggesting that the social vulnerability in this group impacts their health status. Health and social policies and strategies that contribute to the welfare of this population group are required.