Background: - Neonates with very low birth weight are those whose birth weight is between 1000g - 1500g. Around 4-8% of all live births are very low birth weight (VLBW) infant. Around one-third of the neonatal deaths are witnessed in this group. This study has been undertaken with an aims to determine magnitude and risk factors of VLBW babies during their period of hospital stay in VLBW (1 --1.5Kg), so that necessary steps can be taken to reduce the incidence of this VLBW group. Objective: - To assess the magnitude of very low birth weight and factors associated among neonate admitted in HUCSH Hawassa, sidama Ethiopia. Method and Materials: -A simple retrospective cross-sectional study was conducted among 556 neonates admitted in NICU of Hawassa University Comprehensive Specialized Hospital for the last 3 years. Systematic random sampling technique was used to enroll a total study population. Structured questionnaire used to capture the relevant data that was coded and entered into Epi Data version 4 and analyzed by SPSS version 26 and frequency distributions and measures of association was calculated. Result - : Among 556 neonates who were admitted in NICU 103(19.3%) had VLBW . obstetrics complication, neonates body temperature, sex, Hep B result of mother, age of mother, mode of labor, admission diagnosis like sepsis, PNA and RDS are found to be statistically significant with VLBW, an odds and (99%CI) of 2.5(1.44, 4.57), 21.4(3.2,142.3), 0.3(0.16, 0.56), 1.7(0.94,3.32), 2(0.99, 4.35), 3.5(1.34, 9.29), 0.14(0.02,1.01), 2.3(0.84,6.70)and 13.8(6.30,30.38) respectively Conclusion and recommendation:- both maternal and neonatal factors contributed to the risk of VLBW. Strengthening of the existing risk based prevention strategies is essential.