Background:Childhood non-vaccination can have different short-and long-term negative outcomes on their health. In Ethiopia, in addition to low coverage of full vaccination, street children were among the neglected part of the community who were missed during planning and reporting vaccination coverage. Moreover, there is no related research conducted on this title specifically. Objective:The objective of the study was to assess the vaccination status and its associated factors among street children 9-24 months old in Sidama zone. Methods:Community-based cross-sectional study design was conducted in four selected towns of Sidama region, southern Ethiopia. The convenience sampling method was applied to involve mothers of street children younger than two years during the study period. Data entry was done with EpiData version 3.1 and exported to SPSS22 for analysis. Bivariate and multivariable logistic regression analysis were performed to identify factors associated with immunization status of street children. Results:A significant number (26 [24.3%]) of the street children younger than two years were not vaccinated. Those mothers who are ≤20 years old (P = 0.014, AOR = 0.216, 95% CI: 0.064-0.732) and who gave birth at home (P = 0.029, AOR = 0.292, 95% CI: 0.097-0.879) had less odds of vaccinating their child than those older than 20 and who gave birth at health facility respectively. Conclusion:A significant number of the street children in this study are not fully vaccinated. Mothers aged <20 years and home births were significantly associated with non-vaccination status.