Introduction: Postnatal weight gain in very low birth weight babies remains a challenge to the management of the neonatal period in low and middle income countries like Ethiopia, where no many feeding alternatives and follow up charts are available. Even though, extra-uterine growth retardation is a common problem in preterm, very low birth weight babies, there is lack of evidence in resource limited countries on patterns of postnatal weight gain. Therefore this study aimed to assess the Patterns of postnatal weight gain and its predictors among Preterm Very Low Birth Weight Infants Born in Bahir-Dar public hospitals neonatal care unit, 2022.Methods A Retrospective follow-up study was conducted among 206 neonates who were admitted to the neonatal intensive care unit of Bahir Dar city public hospitals for the last 2 years. The calculated sample sizes for each hospital were assigned proportionally. The actual data was collected through structured questionnaires and analyzed by using Stata14.0. Outcome variables were compared using log-binomial regression and reported using adjusted risk ratios (aRR) with 95% confidence intervals and P- value < 0.05 was considered statistically significant.Result The average postnatal weight gain among preterm very low birth weight neonates from regaining birth weight to discharge was 11.1g/kg/d and 85.4% CI (79.9-89.66) of neonates had poor postnatal weight gain at discharge. Preterm very low birth weight neonates delivered by SVD (aRR = 1.38, 95% CI :( 1.34–1.40), delivered after 34 weeks of gestation (aRR = 2.95, 95% CI: (1.62–5.39)), birth z-score >-1.29 (aRR = 3.17, 95% CI: (1.91–5.28)), first feed on the first day (aRR = 2.55, 95% CI: (1.19–5.47)), regaining birth weight within 14 days (aRR = 3.62, 95% CI: (1.45–9.03)) and neonates who had no respiratory distress syndrome (aRR = 3.27, 95% CI: (1.09–9.77) had statistical significant association with adequate postnatal weight gain.Conclusion According to the findings of this study postnatal weight gain for preterm very low birth weight neonates was lower than recommended weight gain by neonatal intensive care unit guideline of Ethiopia. Gestational age, mode of delivery, at birth z-score, initiation time of first feeding, time to regain birth weight and respiratory distress syndrome were factors associated with postnatal weight gain.