BACKGROUND: sarcopenia is a disease associated with muscle changes during aging, and its detection remains a challenge outside specialized clinical units. OBJECTIVE: to evaluate the utility of the Mini-Nutritional Assessment (MNA) in detecting sarcopenia in institutionalized older persons. MATERIALS AND METHODS: we conducted a cross-sectional study in adults aged 55 and older from Puebla. We administered both the short form (SF) and the complete form (LF) of the MNA. We diagnosed sarcopenia according to EWGSOP2 criteria. We plotted the points obtained from MNA-SF and MNA on a ROC curve. We evaluated the odds ratio (OR) for presenting sarcopenia based on the recommended cutoff points using logistic regression models adjusted for age and sex. RESULTS: the study included 162 participants, with 64.1 % of them being women, and the mean age was 69.8 years (SD: 5). The mean scores of MNA-SF and MNA-LF were 12.17 (SD: 1.78), and 25.1 (SD: 2.83), respectively. The prevalence of sarcopenia was 20.4 %. The AUC of MNA-SF was 0.68 (95 % CI: 0.58-0.78), and for MNA-LF, 0.60 (95 % CI: 0.49-0.71). The OR for presenting sarcopenia with MNA-SF <
12 was OR = 2.87 (95 % CI: 1.31-6.29) and, after adjustment for age and sex, OR = 2.47 (95 % CI: 1.10-5.54). CONCLUSIONS: according to AUC, MNA-SF may help detect sarcopenia in institutionalized older persons, while MNA-LF may have reduced utility in practice.