Objective: To verify the trajectory of the functional capacity of elderly persons hospitalized due to clinical conditions in a university hospital. Method: A descriptive, prospective cohort study was conducted between 2015 and 2016. Elderly patients admitted to the Hospital das Clínicas of Botucatu Medical School (Unesp), Brazil, were evaluated for the functional assessment of basic activities of daily living (BADL) using the Katz scale, nutritional status (body mass index (BMI)) and presence of the Frailty Syndrome (FS) (Fried criteria). A description of the trajectory of functional capacity was carried out at four times: 15 days before admission (T0), at admission (T1), at hospital discharge (T2) and 30 days after discharge (T3). Results: 99 elderly people with a mean age of 74 (+7.35) years, 59.6% of whom were male, were evaluated. Of these, 81.8% presented functional independence at T0, 45.5% at T1, 57.6% at T2 and 72.8% at T3. According to their functional trajectories, 28.2% of the elderly lost functional capacity between T0 and T3. There was an association between worsening of functional capacity between T0 and T3 and the FS (RR 4.56; p=0.003). Conclusion: Elderly patients have worse functional capacity at hospital discharge than before hospitalization. About 28.0% of the elderly had worse functional capacity 30 days after discharge than 15 days before admission. The elderly with Frailty Syndrome have a greater risk for worse functional capacity results 30 days after discharge.