Demographic changes show that the older adult population has been growing nationally and globally, increasing odds of falling in this vulnerable population, particularly the in-hospital patient. the Timed Up and Go Test (TUG) assesses functional performance and risk of falling in adults and older adults, with a high level of sensitivity and specificity. However, no evidence that this reliability has been reported in the Colombian population. GOAL: determine inter- and intra-rater reliability of the TUG test, in adult and older adult hospitalized population, in a Colombian institution. Method: The study involved 132 hospitalized adult patients, ages averaging between 40 and 80 years. All participants were interviewed for the registration of their socio-demographic and health conditions and the fulfillment of the inclusion criteria, as well as asked to sign the informed consent. A Test-Retest was conducted for the administration of the TUG, two different times for each participant, with an hour difference between the two assessment moments , recorded the test results independently. None of the physiotherapist researchers who had access to the patients had knowledge of the test results as registered by the peer. The data was systematized in a database and an analysis of Lin¿s concordance correlation coefficient was performed between measures. Results: Inter- and intra-rater reliability for the Timed Up and Go Test for the 132 hospitalized patients by three trained physiotherapists who had 15 to 25 years of experience. It was performed at two different times, in which the physiotherapists took the role of leader and observer of the records for each one of the patients. Spearman¿s Rho coefficients 0.67 in intra-rater tests, 0.97-0.98 in inter-rater. Lin rho Pearson coefficients oscillated between 0.978 and 0.987 (Bland & Altman, 1986). Conclusions: High inter- and intra-rater reliability is found for the Timed Up and Go Test in adult hospitalized Colombian patients