The role of the free radicals in aging has been in center of research for long years. It is assumed that with advancing age, damaging effects of oxygen free radicals might be accumulated in the organisms on all components, especially on the DNA and the mitochondria. In addition, because of the decreased efficiency of the antioxidant systems, the oxidative mechanisms prevail in numerous age-dependent diseases, such as the arterio -sclerosis, Parkinson and Alzheimer diseases. The present study was aimed at revealing an eventual correlation between the free radical levels and the psychophysical health state of an ultraoctagenarian East-Sicilian population living in institutes or at home. Our study population consisted of 125 ultraoctagenarian subjects, 62 of them were institutionalized and 63 living outside the institutes. The free radical effects were measured by using the free radical analytical system (FRAS) assessing the derivatives of reactive oxygen metabolites(D-ROMs). The results are expressed in units of Caratelli (U-CARR). The psycho-physical state of the subjects was estimated by means of the mini mental state examination(MMSE), geriatric depression scale (GDS), activities of daily living (ADL) and instrumental activities of daily living (IADL). The nutritional state and the physical activity of the subjects were evaluated through the mini nutritional assessment (MNA) and the physical performance test (PPT). All studied parameters underwent a correlation analysis of Pearson. Statistically significant negative correlation was found between the free radical levels and the cognitive performance (p < 0.0001), as well as the levels of autonomy and autosufficiency,the physical activity in the total population (p < 0.01). These correlations were even more expressed in the institutionalized subjects. Statistically significant positive correlation seems to exist between the free radical levels and the nutritional status (p < 0.001). These studies revealed some important differences between the institutionalized and noninstitutionalized population. The levels of oxygen free radicals were higher in the former group, indicating a stronger oxidative stress, influencing the psychophysical state of the elderly subjects. This may have negative consequences on the quality and duration of the life. It is difficult to define the exact role of free radicals in the determination of aging pattern,but they may be considered without any doubt as true "markers" of an enhanced oxidative stress, accompanying a non-successful aging process.