Background: The public health problem of undernutrition is common in Ethiopia, particularly among children aged 6–59 months. However, determinants of undernutrition among children in this age group are not well investigated particularly within the context of COVID-19 pandemic. This study was, therefore, designed to assess the magnitude and determinants of undernutrition among children aged 6–59 months at Tirunesh Beijing general hospital, Ethiopia. Methods and materials: An institutional-based cross-sectional study was conducted involving 283 children aged 6–59 months in March 2022. The data were collected using structured questionnaire and anthropometric measurements. Undernutrition was defined as a Z-score value of weight for height (WFH), height-for-age (HFA), and weight-for-age (WFA) <2SD as calculated by the world health organization plus software. A multivariable logistic regression model was used to identify the independent factors associated with undernutrition. p-values less than 0.05 were considered statistically significant. Results: The response rate in this study was 97.9%. The overall magnitude of undernutrition was 34.3%, of which 21.2%, 12.7%, and 9.5% were stunted, underweight, and wasted, respectively. Occupation of mothers [AOR = 13.64, 95% CI (4.21–14.77)], amount of meal [AOR = 14.68, 95% CI (4.09–52.81)], feeding by caregivers [AOR = 8.96, 95% CI (2.81–18.60)], and breastfeeding [AOR = 0.06, 95% CI (0.02–0.22)] were significant predictors of undernutrition. Conclusions: The prevalence of undernutrition among children under the age of five remains high. Therefore, promoting breastfeeding and motivating children to feed adequate amount of meal are recommended. Besides, counseling and/or guiding caregivers on how to feed children shall be suggested. The findings could help inform the design and prioritization of effective intervention strategies at early life stage.
