Sarcopenia is probably an important causal factor for functional decline in acutely ill hospitalized geriatric patients. Low skeletal muscle mass, low gait speed and low grip strength are hallmarks of diagnosing sarcopenia. However there are many different diagnostic criteria to assess sarcopenia.In this study the influence of different criteria for sarcopenia was studied on sarcopenia prevalence in geriatric patients admitted to an acute care hospital.Cross sectional study design.A geriatric ward of a large Dutch hospital.Geriatric patients.Skeletal muscle mass measured using bio impedance analysis (BIA), gait speed using the 4 meter walking test and grip strength. The sarcopenia prevalence was investigated according to criteria of: muscle mass, grip strength, the European Working Group on Sarcopenia in Elderly People, the International Working Group on Sarcopenia and the Special Interest Group of Society of Sarcopenia, Cachexia and Wasting Disorders.85 geriatric patients were included (61 women). Applying the 17 different criteria, the sarcopenia prevalence varied from 26-75% for women and from 42-100% for men. Comparing the Janssen calculation with the Maltron calculation sarcopenia prevalence ranged from respectively 26-67% and 67-70% for women and from 42-71% and 75-100% for men. Almost all patients (96%) had a low gait speed.Sarcopenia is highly prevalent in an acute hospitalized geriatric population, although the prevalence varies widely depending on the diagnostic criteria applied. A prospective study is needed to discover which criteria of sarcopenia can predict best adverse outcomes.