Background: Infant and young child feeding is a cornerstone of care for childhood development. Optimal Infant feeding practice is one of the challenging issues on prevention of mother to child transmission of HIV particularly in developing countries due to the benefits and risks of exclusive breast feeding replacement and mixed feeding practice. Objective: The aim of this study was to assess infant feeding practice and associated factors among HIV positive mothers attending ART service in governmental health institutions of Woldia town. Methods: Institution based cross- sectional study was conducted in 3 health institutions which provides ART service in Woldia town from October to November 2021. Systematic sampling technique was used to select 316 mothers’ infant pairs. The data were collected using interviewer administered-structured questionnaire. The data was checked, coded and entered to SPSS version 20 for analysis. Both bivariate and multivariable analyses were used to identify associated factors for infant feeding practice. Result: The majority 79.4% practiced exclusive breast feeding up to six months of age. 9.5% and 11.1% of mothers practiced exclusive replacement feeding and mixed feeding, respectively. On Multivariable logistic regression model, Mother‘s educational status (AOR (95%CI፡ 12.39(2.605, 58.963), Attending ANC visit AOR (95%CI: 0.219(.068, 0.793), Attending PNC visit (AOR (95%CI: 3.92(1.47, 10.48) and Heard about recommended infant feeding (AOR (95%CI፡ 6.02(2.17, 5.224), were significant positive predictors of safe infant feeding practice. Conclusion: The study revealed that majority 88.9% of the mothers practiced safe feeding. Mothers Educational status, Attending Antenatal Care follows up, Attending Post Natal Care and heard about recommended infant feeding were significantly associated with safe infant feeding practice. Key words: infant practice, HIV positive mother