Background : World Health Organization has identified length of birth interval as arncritical determinant of child mortality risks and recommended women to space their birthsrn3-5 years apart to reduce health risks to both children and mothers.rnObjective: To determine duration and determinants of birth interval at selected publicrnhospitals of Addis Ababa. Method: A facility-based, cross-sectional study design wasrnconducted in Addis Ababa city selected public hospitals. A simple random samplingrntechnique was used to select 375 study participants after the sampling procedure was done.rnThe data was collected using structured and pre-tested, interviewer-administeredrnquestionnaire from November 20 to December 20, 2020. Bivariate and multivariablernlogistic regression were done to identify factors associated with birth interval using oddsrnratio at 95% C.I and P-value < 0.05 was considered statistically significant. Result : Arntotal of 375 respondents participated in the study which makes the response rate of 100 %.rnMean birth interval of the study population was 36.2 ± 5.8 months and the median birthrninterval is 37 months. This study found that short birth interval practice was 31 %.rnConclusion and recommendation: Short birth interval practice was high in the study area.rnFactors associated with birth interval were maternal education, mother’s occupation, sex ofrnchild, maternal age, length of contraceptive use, duration of breast feeding, ANC follow uprnand place of delivery. Effective counseling on family planning services should be applied.