Objective: To estimate the prevalence of STI (including HIV) among low risk behavior population groups in 5 provinces/cities of Vietnam in 2003. Methodology: This was a cross sectional study with convience sampling. The total sample size of study was 4,000 subjects including 2,000 military reruits, 2,000 pregnant women (low risk group). Forthis population, urine specimens w,ere colleted and tested by the PCR for C trachomatis and N. gonorrheae, serum for RPR/TPHA and HIV testing. For pregnant women wet mount preparation for T. vaginalis and C albicans. Results: Among the subjects examined, the prevalence of STI are shown in the table below (percent). Conclusions: The high prevaience of CTrachomatis and HIV in military recruits suggests that efforts to reach these groups may represent an important adjunct to current prevention efforts, which focus largely on screening them.