Background: HIV/AIDS and malnutrition effects are interrelated and exacerbate each other in a vicious cycle. HIV/AIDS prevalence in Amhara region is more than the national one and studies in Bahir Dar city do not contain all nutritional factors full that affect due actions. Objective: To assess the association among knowledge, practice and associated factors towards proper nutrition among adult P eople Living with HIV (PLHIV) in Bahir Dar city . Method: Institution based cross-sectional study with sample size of 376 was conducted in Bahir Dar city from April to mid July, 2022. The sample size was proportionally allocated to four associations of the PLHIV and each sample was selected by systematic random sampling method. The data were collected using interviewer administered questionnaire, coded and entered into Epi Info 7 & analyzed using SPSS version 20. Descriptive and inferential statistics were methods of data analysis using odds ratio with 95% confidence interval. Result: A total of 376 respondents with the mean age and SD of 37.6 years ±7.5 were participated. The overall mean score of nutrition knowledge was 15.26±2.6. About 54% and 51.3% of respondents’ nutrition knowledge and practice were above the mean. Respondents who read and write, who had primary education, and with secondary and above education level had 2, 3 and 6 times more nutrition knowledge than who do not read and write respectively. Males had 2 times more likely practiced nutrition as compared to females. Respondents with no nutritional and health problem & having good knowledge on nutrition had about 2, 3 and 3 times more nutrition practice respectively than those with nutritional problem, health problem and poor nutrition knowledge. Conclusion and recommendation: Greater than fifty percent of PLHIVs responded to nutrition knowledge and practice above the mean. There is a strong relationship between nutrition knowledge and dietary practice. Hence, scientific nutrition education and counseling should be key components to the care of PLHIV and initiated at the entry point to the comprehensive care. Associated factors also influence nutritional practices of PLHIV. Therefore, special attention should be given to illiterates, daily workers, those with nutrition and health problem and other groups with low nutritional knowledge and practice as displayed in the bivariate and multivariate result tables 5 & 6. Keywords: Nutrition knowledge, nutrition practice, PLHIV, nutrition among PLHIV.