Undernutrition is the imbalance between the intake of nutrients, energy and the bodily requirements to live, grow, and carry out specific functions, especially before reaching the age of five. This study is aimed at assessing maternal perception of factors contributing to undernutrition among under-five children in selected primary healthcare facilities in Abeokuta South Local Government Area, Ogun State, Nigeria. Factors contributing to undernutrition such as low parental education, income, family size, challenging employment, poor living conditions, and inadequate dietary intake, were identified as significant determinants.

Study Design:  The study was descriptive design.

Place and Duration of Study: Primary Health  Care facilities in Abeokuta South Local Government Area, Ogun State  between July 2023 and October 2023.

Methodology: 80 questionnaires were distributed to the respondents.  Data was analyzed using SPSS version 22 and was presented using frequency, percentage and distribution.

Results: The knowledge of undernutrition among respondents showed that 86.3% of respondents believed that an imbalanced diet is the cause of undernutrition and 37.5% of the population demonstrated a low level of knowledge and 62.5% of the population had a high level of knowledge of undernutrition in children. Respondents’ perception of factors responsible for undernutrition in children revealed that 91.3% of respondents claimed that cultural beliefs and traditional practices have a great influence on nutritional practices. Also, 31.2% of the population had a poor perception while 68.8% of the population had a good perception of the factors associated with undernutrition in children.

Conclusion: The findings demonstrate a high prevalence of undernutrition, specifically stunting, Factors found to be significantly associated with poor nutrition outcomes in children under five are unsafe drinking water and sanitation, maternal height, birth order and age of the child.

Keywords: Socio-demographic, Undernutrition, Respondent, Knowledge, Health concern