Health problems are substantially increased in homeless populations who have higher prevalence's of infectious diseases than do general population. They have relatively earlier onset of sexual activity, and due to lack of information, many facilities for the practice of unprotected sex and low level of condom usage increase the risk of sexually transmitted infections (STIs). This study aims to identify the knowledge and prevention of STIs among homeless people. An analytic cross-sectional study was conducted in a Tbilisi municipal shelter. Within the framework of the quantitative research, the beneficiaries were interviewed with a self-administered questionnaire. Most of the respondents (98%) have heard about STIs, but their health literacy is low. Although respondents knew the risk factors for STIs, they had a high degree of risk-taking sexual behavior evidenced by the very low percentage using condoms (15.2%) and a large proportion having multiple partners (54.3%). It is necessary to raise awareness about STIs and promote sexual education of respondents at the municipal shelter.