Abstract Background:Maternal malnutrition and infant feeding mode impact short and long term infant and child morbidity and mortality. The period of lactation may provide an opportunity to modulate the risk of disease later in life. Our aim was to estimate the effect of maternal body mass index (BMI) and infant feeding mode, particularly breastfeeding practices, on the anthropometric status of children under two years in Colombia. Methods:A secondary analysis was performed using the data from ENSIN 2010. Term infants under 2y, singleton, with a mother older than 18y were included in the analysis. Outcomes were wasting (WLZ<-2SD), overweight (WLZ>+2SD) and stunting (LAZ<-2SD). Predictors were infant feeding (exclusive and predominant BF constructed from 24 hour recall, age at introduction of liquids, semisolids and solids) and maternal BMI. Socioeconomic variables, maternal education and age, conditions during pregnancy and birth weight were analyzed as covariates. Results:Mothers of overweight infants had higher BMI (Mean dif=-1.47 kg/m2; 95% CI=-2.1, -0.8) than those with normal weight infants. Stunting and wasting were not predicted by maternal anthropometry or infant feeding mode. Maternal education was associated with wasting (OR=0.90; 95% CI=0.86, 0.97; p=0.003) overweight (OR=1.06; 95% CI=1.02, 1.01; p=0.001) and stunting (OR=0.92; 95% CI=0.89, 0.94; p<0.0001); birth weight was associated with overweight (OR=1.001; 95% CI=1.00, 1.001; p<0.0001) and stunting (OR=0.99; 95% CI=0.89; p<0.0001) in the final regression model. ​ Conclusions:Maternal BMI is a modifiable target for public health policy to promote healthy infant growth. Infant nutritional status is affected by direct and indirect factors that need to be addressed in further studies.