Background: This paper aimed to evaluate the effects of an integrated physical fitness curriculum on the physical fitness of Hong Kong preschoolers aged 3-6 years over a period of three years.Methods: Three cross-sectional studies were conducted, one in each of the academic years from 2015/2016 to 2017/2018 on preschoolers’ physical fitness. The integrated physical fitness curriculum was implemented in the second term of the three years in all participating kindergartens, with the data collected in the first year as the baseline. The second data collection was done in 2016/2017 and the last one in 2017/2018. The outcome measures included the preschoolers’ body mass indices and their physical fitness parameters like sit and reach, standing long jump, bean bags throwing, balance beam walking, and continuous jump with both feet. Ethical approval was obtained from the Human Subjects Ethics Committee of The Education University of Hong Kong.Results: The study enrolled 11,181, 10,815, and 6,309 preschoolers in the academic years 2015/2016, 2016/20017, and 2017/2018 respectively. The participants aged 4, 5, and 6 demonstrated significant improvement in most physical fitness parameters in 2016/2017 and 2017/2018 as compared with those of the same age in 2015/2016. Those aged 3, who had never been exposed to any of the interventions, had poorer performance in most physical fitness parameters. Significant improvements in both body mass indices and their physical fitness parameters were evidenced after the interventions.Conclusion: An integrated physical fitness curriculum can enhance the physical fitness of Hong Kong preschoolers for better health. Copyright © 2019 International Journal of Science and Healthcare Research.