Sarcopenia is a common condition in older and frail populations, and it has been associated with adverse health outcomes. However, impact of sarcopenia on mortality in hospitalized older adults has rarely been evaluated. Aim of the present study was to investigate the association between sarcopenia and mortality during hospital stay and at 1 year after discharge in older individuals admitted to acute care wards. This is a multicentre observational study involving 770 in-hospital patients. Muscle mass was quantified with the bioelectrical impedance analysis. The diagnosis of sarcopenia was based on the algorithm proposed by the European Working Group on Sarcopenia in Older People (EWGSOP). After discharge, participants were followed for 1 year. Mortality was assessed during hospital stay and during 1-year follow-up. Within the 770 participants (mean age: 81 ± 7 years, 56% women), sarcopenia was present in 214 (28%) of them, 22 participants died during hospital stay, and 113 in the year after discharge. Participants with sarcopenia had a significantly higher in-hospital (6% vs 2%; p = .007) and 1-year mortality (26% vs 14%; p < .001) as compared with participants without sarcopenia. After adjusting for potential confounders, sarcopenia resulted significantly associated with in-hospital (hazard ratio: 3.45; 95% CI: 1.35-8.86) and 1-year mortality (hazard ratio: 1.59; 95% CI: 1.10-2.41). Sarcopenia is a prevalent condition among older adults admitted to acute care wards and it is associated with increased short- and long-term mortality in hospitalized older adults.