To determine the effect of a self-care program on oxidative stress (OxS) and cognitive function in an older, Mexican, urban-dwelling population. A longitudinal and pre-experimental study was carried out in a sample of 79 older healthy, urban-dwelling individuals residing in Mexico City, (62 females and 17 males), of which 71 of them (59 women and 12 males) complied with the entire self-care program. We measured OxS, cognitive function, the Nagi Disability Scale of physical task functioning, and Instrumental Activities of Daily Living (IADL) prior to and after 2 years of intervention with an active aging program. All older persons adopted healthy, self-care-based lifestyles according to the active aging program to which they were trained, which was associated with a statistically significant improvement of OxS and cognitive function markers on comparing pre- and post-community intervention data. Our findings suggest that self-care-based healthy lifestyles programs can improve the oxidative stress and cognitive function in urban-dwelling elderly population.