We aimed to assess the prevalence and risk factors of chronic malnutrition in children under five years old in Aydin province, Turkey. A cross-sectional design was used to study a group of 1,400 children. Multistage sampling, including cluster and random sampling, respectively, was used in the selection of the study group. Stunting, wasting and underweight were used as indicators of nutritional status for children. The prevalence of malnutrition in children under five years was found as 10.9% for stunting, 4.8% for underweight and 8.2% for wasted. Increased risk was found in families without social security by 2.071, with low birth weight by 2.516 and with giving no colostrum by 2.787 in stunted children. Improving social security coverage is essential. Mothers should be informed on the usefulness of breast-feeding at antenatal care services during their pregnancies and taught appropriate breast-feeding practices, including the importance of giving colostrum, at baby-friendly institutions after birth.