BackgroundDetermining the magnitude and risk factors of undernutrition in a country that has one of the highest prevalence of undernutrition in the world is paramount for developing contextual interventions.MethodsThis study used baseline data from the ASSP project to estimate prevalence of stunting, wasting, and underweight in four provinces of DRC. It involved 3911 children aged 0–59 months old and mother pairs. Height-for-age Z scores, Weight-for-height Z scores, and Weight-for-age Z scores were calculated and used to classify child stunting, wasting and underweight respectively, based on the 2006 World Health Organization (WHO) growth reference. Hierarchical logistic regressions were used to identify risk factors associated with stunting, wasting and underweight. All analyses were conducted using STATA 15.1, and statistical significance was set at p < 0.05.ResultsThe prevalence of stunting, underweight and wasting was 42.7%, 21.9% and 8.2% respectively. Increasing child’s age was a risk factor associated with stunting and underweight, while sex was not associated with the 3 indicators of undernutrition. Low levels of mother’s education, mothers working in the last 12 months prior to the survey, children living in the province of Kasai occidental, children born at a health facility, children perceived by their mothers to be born very small were associated with higher risks of stunting. Factors associated with underweight were children from the province of Kasai occidental, mothers who worked in the last 12 months prior to the survey, and children perceived to be born very small or small by their mothers. Children born to mothers aged 35–49 years and children breastfed in combination with drinking water were at higher risk of wasting.ConclusionPrevalence of undernutrition in DRC is high. This study has identified certain modifiable risk factors associated with stunting, wasting and underweight. To reduce the burden of undernutrition in DRC, authorities should target factors at individual and community levels by improving women’s education, child feeding practices and promoting agriculture.