Background: Globaly11% of a population is living in hunger and affected with all form of malnutrition due to different factors. About 14 million adolescent girls worldwide become lactating mothers each year and more than 90% of these are very young and reproductive mothers live in developing country. Adequate nutrition for the mothers during lactation is important for their health as well as for their children. However; there is limited information on maternal nutrition status and associated factors in low-income countries including Ethiopia, especially in the study area. Objective: To assess nutritional status and associated factors among lactating mothers in Burie district, North West Ethiopia Method: Community based cross sectional study design was conducted. A total of 570 lactating women were included in this study. Data on socio-demographic, economic, health service related characteristics were collected by interview. Body Mass index was used to measure the nutritional status of the lactating mothers. The data was analyzed using Statistical Package for the Social Science (SPSS.version.23). Descriptive statistics, bivariate and multivariable logistic regression analysis were performed. The measure of association between dependent and independent variables were assessed using the odds ratio with a 95% confidence interval and variables with p-value ≤0.05 consider significant. Result: About 19.6% of lactating women were underweight (BMI < 18.5 kg/m2). The result revealed that lactating mothers who had primary educatio n was 5 times more likely to be underweight than lactating mothers who had more than secondary and above education (AOR = 5.4, 95%CI: 1.16, 23 ;).On the other hand, mothers who have family size greater than or equal to eight was 3 times more likely exposed to underweight than those lactating mothers who have 4-5 family size. (AOR=3.3, 95%CI=1.06-10).women whose age of first pregnancy less than 18 years old was 4.1 times more likely to be underweight than lactating mother who had more than 25 and above years of old (AOR, 4,95% CI: 1.6, 10). Those mothers who had no sufficient information or health education about nutrition during lactating were 2 times more likely to be under weight than those mothers who had health education about food during lactating (AOR=2 95%CI=1.3, 15). Conclusion and recommendation: Nutritional status of lactating women in the study area is poor. About 19.6% of lactating women were underweight. Factors associated with underweight of lactating women include; family size, educational status women, age of first pregnancy and health education about nutrition. Community-based nutritional education is important to improve women nutritional status: Local government of the study area should give emphasis on lactating mother’s nutritional status by providing family planning services and improving educational status of females and delaying age of first pregnancy. Keywords: cross sectional, lactating mothers, nutritional status, Burie North West Ethiopia