Background: - Malnutrition among people living with HIV remains a major challenge in achieving the full impact of interventions aimed at improving the quality of life, productivity and survival. However, the outcome of ready to use food therapy and factors affecting it among HIV/AIDS patients are not yet well investigated. Objective: - This study aimed to assess the outcome of ready to use food therapy and its predictors among adults’ HIV/AIDS patients at Felege Hiwot Comprehensive Specialized Hospital, North west Ethiopia, 2020. Methods: - Retrospective cohort study was conducted among 636 adult HIV/AIDS patients on food by prescription at Felege Hiwot Comprehensive Specialized Hospital from November 30,2020 to December30, 2020. The study subjects were selected by systematic random sampling method using food by prescription registers as sampling frame. Data were entered and cleaned using Epidata version 3.1 then export to SPSS version 23 for analysis. Logistic regression was used to identify the association between dependent and independent variables. Variables with a p -value < 0.25 in bi-variable analysis were included into a multivariable logistic regression analysis to identify the predictor variable. Log Binomial logistic regression was used for a better estimation of RR. Variables with p-values less than 0.05 during Log Binomial logistic regression analysis was considered statistically significant with 95%CI. Results: - In this study 36.8% of patients on ready to use food therapy were recovered. Severity of malnutrition at enrollment AOR (95% CI) =7.041 (3.719-13.331)], presence of opportunistic infection [AOR (95%CI) = 15.563 (6.417-37.745)] and Adherence to RUFT [AOR (95% CI) = 8.784 (1.314 -58.702)] were the predictors of outcome of ready to use food therapy. Conclusion and Recommendation: -The recovery rate of this study was lower than the sphere standard. The factors that affect Outcome of ready to use food therapy were severity of malnutrition, opportunistic infection and adherence to RUFT. Regular and comprehensive nutritional screening of patients on HIV chronic care, early treating of OI and strengthening of nutritional adherence counseling for patients on RUFT is very crucial to improve recovery. Keywords: -Food by prescription, Predictors, Treatment Outcome, Ethiopia