Introduction Aging is a process of morphologic and physiologic changes that naturally predisposes elderly persons to progressive health decline. Vulnerability to poor resolution of homoeostasis after a stressor event may represent the common pathway of elderly cognitive, physical and psychological fragility. Regular physical activity (RPA) has been shown to have positive effects in cognitive performance, stress and mood state. Aims We aimed to study the relationship between RPA, salivary cortisol, emotional and cognitive state in institutionalized elderly women. Methods A cross-sectional study was performed in 35 institutionalized women (mean age of 81.5 [7.5] years). Participants were divided in active (ACT, n = 20) and insufficiently active (IACT, n = 15) according with the International Physical Activity Questionnaire (IPAQ-sv). The Center for Epidemiological Studies Depression Scale (CES-D), Subjective Happiness Scale (SHS) and Mini-mental State Exam (MMSE) were applied. Salivary levels of Cortisol were analyzed by Elisa. The t -student test was used to compare groups and associations between variables were detected using Pearson's correlation coefficients. Results Participants from the ACT group presented higher MMSE ( P = .037) and lower CES-D scores ( P = .028). Although Cortisol presented similar levels in both groups, a negative correlation was detected between cortisol and the CES-D score. A negative association was also found between the presence of depressive symptoms and MMSE. Conclusion A higher physical activity was associated with lower cognitive impairment and less depressive symptoms, reinforcing the positive influence of RPA in the elderly. Furthermore, higher subjective well-being is associated with the maintenance of cortisol levels and an adequate stress response. [ABSTRACT FROM AUTHOR]