Background: Reproductive tract infection (RTIs) is a common disease among women. Limitation in understanding about RTIs is one of the risk factors of RTIs. This study aims to evaluate knowledge, attitude and practice of RTls prevention among mountainous married women at reproductive age in Thai Nguyen province 2013. Subjects and methods: A cross-sectional descriptive study was conducted among mountainous married women at reproductive age in Thai Nguyen province. Results: A total of 1,200 women, the majority (43.4 percent) aged from 25-34, were farmer (64.7 percent), over half (53.3 percent) were educated to primary school or under level. The prevalence of high knowledge of RTls prevention was 19.5 percent, moderate knowledge was 21.8 percent and low knowledge was 58.8 percent. Prevalence of good attitude of RTls prevention was 60.5 percent and 39.5 percent was not good. Prevalence of good practice of RTls prevention was 20.0 percent and 80.0 percent was not good. Conclusion: Knowledge, attitudes and practice of RTls prevention among mountainous married women at reproductive age is not high.