Objective: The purpose of this study was to investigate the validity and reliability of the Timed Up and Go Test (TUG) among normal 3-5 years old preschool children in Hong Kong. Methods: Cross-sectional design was applied to this study. Sixty (30 female, 30 male) preschool children aged from 3 to 5 years old (mean age=4.22 ± 0.85) from local normal preschool was recruited using convenient sampling to perform three dynamic balance tests: Timed Up and Go Test (TUG), Star Excursion Balance Test (SEBT) and the Pediatric Balance Scale Test (PBS). A simple self-administrative questionnaire survey was also conducted with their parents. Results: Positive correlation (r=0.74, p<0.05) was found between TUG results obtained at two time points when assessing the test-retest reliability. Moderated negative correlations were found between TUG and SEBT or PBS, which indicated children with longer reaching distance or higher PBS score tend to use shorter time to complete TUG. Conclusion: TUG was a valid and reliable tool for assessing dynamic balance of preschool children aged between 3 and 5 years old. This can also be used for screening or early detection of developmental coordination disorder (DCD) for children aged 6 years old or younger.