Aim To determine the prognostic value for mortality of physical function tests, muscle mass loss, disability and frailty in elderly hospitalized patients. Methods We prospectively included 298 hospitalized patients aged >60 years (152 men and 146 women). We assessed comorbidity using the Charlson Comorbidity Index; nutrition by body mass index, midarm muscle area and subjective nutritional score; physical muscle function by handgrip strength, gait speed, standing balance and stand up test; disability using the Barthel test and activities of daily living; frailty by the clinical frailty scale and Fried frailty index; and cognitive impairment by the Pfeiffer test. We assessed 100‐day and long‐term mortality. Results We found a high prevalence of malnutrition, comorbidity, cognitive impairment, physical function impairment, disability and frailty. Mortality at 100 days was 15.1%, with a long‐term median survival of 989 days. Mortality was significantly related to age, comorbidity, nutritional status, physical function, disability and frailty. Serum vitamin D3 levels were not related to mortality. Independent prognostic value for long‐term mortality was shown by: (i) incapacity to carry out any of the walking, stand up and standing balance tests; (ii) male sex; (iii) aged >80 years; (iv) impaired handgrip strength or gait speed; (v) Charlson Comorbidity Index ≥1; and (6) impaired muscle mass of subjective nutritional score. Conclusions In elderly hospitalized patients, there is an important role of muscle regarding prognosis, mainly related to physical function, but also and independently regarding muscle mass. Geriatr Gerontol Int 2017; ••: ••–••.