BACKGROUND: Malnutrition refers to deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients. The term malnutrition is a broad term encompassing the three conditions namely undernutrition (micronutrient-related malnutrition), over-nutrition (overweight and obesity), and diet-related non-communicable diseases. Undernutrition is defined as the outcome of insufficient food intake and repeated infectious diseases. Low birth weight (LBW) is cited as a risk factor for mortality and morbidity in young children. However, its association with undernutrition has received little attention. Thus, the current study aimed to examine the relationship between LBW and undernutrition in Malawi. METHODS: A cross-sectional study was conducted using data from the Malawi Demographic and Health Survey (MDHS) 2015-16. Children whose Z-scores for each of the following indices height-for-age, weight-for-height, and weight-for-age were below the minus two standard deviations (-2SD) from the median of the World Health Organization's (WHO) reference population were considered to be stunted, wasted and underweight, respectively. LBW was defined as babies whose birth weight was less than 2500 g. The multivariate logistic regression models were performed using surveylogistic while controlling various confounding factors in the six different models. RESULTS: The prevalence of stunted, underweight, wasted, and LBW were reported as follows, 39%. 11, 2, and 10% respectively. Compared to children with normal/average birth weight, those with LBW had significantly higher odds of being stunted [adjusted odds ratio (aOR): 1.72; 95% confidence interval (CI): 1.35-2.20), underweight (aOR: 2.30; 95% CI: 1.68-3.14) and wasted (aOR: 1.47; 95% CI: 1.38-4.25) respectively. CONCLUSIONS: LBW was a strong predictor of all the three indices of undernutrition. Interventions that aim at improving the growth and development of children during the early years should consider addressing factors that trigger LBW.