Background: This paper explores changes in the well-being of a group of people ages 65 and over in the city of Buenos Aires, Argentina during the stay at home mandated by the government in response to the COVID-19 pandemic (March to November 2020). Due to its higher level of risk, this population group was subjected to specific isolation measures. Subjects and methods: The study objectives were 1) To identify the determinants of psychosocial well-being of people ages 65 and over, and 2) To describe the longitudinal variation in well-being in this population. Data was collected three times over a sixty-day period. A well-being scale was generated using a subset of the Clinical Interview Schedule - Revised (CIS-R) questions commonly used in the United Kingdom and validated by the World Health Organization. Results: Statistically significant associations were found between levels of well-being and feelings of loneliness and selfreported health, gender, and exposure to mass media. Conclusions: While the level of psychosocial well-being across the sample remained relatively constant, psychosocial well-being varied within individuals during the period under study. Self-reported health, feelings of loneliness and gender played a key role in predicting psychosocial well-being. Recommendations for public policy intervention are offered.