Discomfort that is often felt by street children in utilizing health services occurs because of negative perceptions of themselves which come from themselves and surrounding environment. This caused street children as marginal groups, as they do not have the confidence to access health services. This condition is complicated by the limited health services for adolescents. Street children need to develop self-efficacy that can build their confidence and courage in the process of seeking treatment. This study aims to describe self-efficacy which is an internal factor that can influence the behavior of street children in seeking health services. Cross sectional quantitative research with simple random sampling method used to retrieve 115 samples of the children-on-the-street aged 12-20 years in five urban areas in Indonesia, namely Jakarta, Bogor, Depok, Tangerang and Bekasi (JABODETABEK). The results showed that self-efficacy variables could influence the behavior of street children using health services (OR= 3, 847). These results proved that street children with high self-efficacy had four-times potential of behavior in utilizing health services compared to street children with low self-efficacy. This also proved that increasing self-efficacy could help street children to have healthy behaviors and improve their ability to monitor their health independently. Increasing self-efficacy is one of the effective strategies to overcome health problems in street children.