Background: Inadequate intake of both macro and micronutrients of lactating women was prevalent. But, little study was conducted in Ethiopia regarding to nutrient intake inadequacy of lactating women. Objective: To assess nutrient intake inadequacy and its associated factors among lactating women in Bahir Dar City, North West Ethiopia, 2021 Methods: Community based cross sectional study was conducted from February 15 to March 05, 2021 in Bahir Dar city. Three hundred nighty six respondents were selected through systematic random sampling. Data were collected by interviewer administered semi structured questionnaire and a single multiple pass 24 hour dietary recall was used to assess dietary assessment. Data entry and analysis were carried out using EpiData and SPSS respectively. The ESHA food processor, Ethiopian, Kenyan and Tanzanian food composition table were used as the calculation of nutrient values of the selected nutrient. The nutrient intakes were assessed by Nutrient Adequacy Ratio (NAR) and Mean Adequacy Ratio (MAR). Multivariable binary logistic regression analysis was done to identify the factors of overall nutrient intake inadequacy (p<0.05) and the strength of association was measured by Odds Ratio (OR). Result: The overall prevalence of nutrient intake inadequacy across 14 nutrients was 40.4 % [95% CI (35.5, 45.5)]. The median intake of energy, protein, carbohydrate, and fat were 2397.1 kcals, 106.2g, 445.6g, and 27.1g respectively. The percentage of energy from protein, fat and carbohydrates was 15%, 10% and 75%, respectively. The inadequate intake of vitamin A was 98.2%. Similarly the inadequate intake of B vitamins ranges from 13.4% to 68.5%. The insufficient intake of calcium, iron and zinc were 70.9%, 0% and 4.7% respectively. On multivariable logestic regression analysis; Being divorced was 5.1 times more likely to had overall nutrient intake inadequacy than married [AOR= 5.06, 95% CI (1.71, 15.03)]. The odds of overall nutrient intake inadequacy was 2.3 and 2.0 times higher in merchant and government employee respectively than housewives [AOR= 2.33, 95% CI (1.25, 4.34)] and [AOR=2.02, 95% CI (1.13, 3.59)]. Having poor nutritional knowledge were 2.4 times more likely to had overall nutrient intake inadequacy than good nutritional knowledge of lactating women [AOR=2.41, 95% CI (1.32, 4.43)]. Conclusion: Overall, the nutrient intake in lactating women was lower than the recommended levels. Nutritional knowledge, marital status and occupational status of lactating women were the significant factors of overall nutrient intake inadequacy. Key words: lactating women, nutrient, adequacy, Bahir Dar City, Ethiopia