Purpose Few studies of vision screening in school-aged children were reported in Tibetan Plateau. We herein summarize the results of a mandatory vision screening conducted in young children in the Tibetan Plateau of Southwest China. Methods The Lhasa Childhood vision Screening (LCVS) performed uncorrected distant visual acuity (UCVA) test on primary school students in urban Lhasa from July to September 2019. Pin-hole corrected VA (PCVA) was obtained for individuals with the UCVA less than 20/25. Decreased VA was defined for UCVA based on the American Academy of Pediatrics guidelines 2016 (UCVA < 20/32 for over 60 months). Visual impairment (VI), Mild VI, and moderate VI to blindness, defined as a PCVA less than 20/40, less than 20/40 to 20/63 and less than 20/63 in the better eye, respectively. Results Overall, 34,848 children aged 9.03 +/- 1.87 years fulfilled the screening with a response rate of 98.5%. 18,412 (52.8%) of the participants were males, and 30,531(87.6%) were Tibetan. The prevalence of decreased VA, VI, Mild VI, and moderate VI to blindness was 35.6%, 4.4%, 3.5%, and 1.0%, respectively. The prevalence of decreased VA in grade 1-6 students was 28.8%, 20.8%, 26.9%, 40.7%, 50.8%, 59.5%, respectively. The prevalence of VI in grade 1 to 6 students was 1.5%, 1.4%, 2.4%, 5.6%, 7.7% and 9.9%, respectively. Conclusion This study documented a relatively low prevalence of decreased VA and VI in Tibetan primary school students than other urban populations in China. An increasing trend of poor vision with grades was found.