In the last decades, due to the reduction of mortality rates and the fall of birth rates, there has been a transformation in Brazil's demographic profile, which has increased longevity, and consequently, in the expressive number of elderly people. With the life expectancy's increase, functional alterations arise that can compromise the functional independence and quality of life of this population. Among the most relevant aging-related alterations is the Frailty Syndrome of the Elderly (FFS). This syndrome is considered highly prevalent, resulting in dramatic consequences to the health of the elderly. North American data show a prevalence of 7 to 12%, and in Latin America and some Caribbean countries, the prevalence has increased considerably, being 30 to 48% in women and 21 to 35% in men. These rates far exceed not only North American data but also data from European countries. OBJECTIVE: To analyze the relation between age and body composition of institutionalized fragiles elderly women. METHODOLOGY: Forty elderly women, aged ≥70 years, diagnosed with SFI without dementia and/or depressive features were selected. After body mass index (BMI) determination, classification into three groups was performed (n=6 underweight <22 kg/m2, n=13 eutrophic 22 to 27 kg/m2, and n=21 overweight >27 kg/m2), total muscle mass index (TMSI) by predictive equation, and handgrip strength (HGS) by dynamometry were also evaluated. RESULTS: Significant differences were found in the means of BMI (underweight 20.1; eutrophic 25.2 and overweight 30.5; p<0.000) and IMMT (underweight 4.9; eutrophic 6.3 and overweight 7.8; p<0.000). Both indices decreased with advancing age. The mean IMMT was lower than normative values (5.9 to 9.5 kg.m-2) only in the low weight group. Although no significant differences were found