Maternal Knowledge, Attitude and Compliance Regarding Completion of Under-Five Immunisation at Oba Ademola II Maternity Hospital, Abeokuta, Ogun State, Nigeria

Introduction: Immunisation remains one of the most cost-effective public health interventions for reducing childhood morbidity and mortality from vaccine-preventable diseases. Despite its proven benefits, many under-five children in Nigeria remain partially immunised, often due to maternal knowledge, attitude, and compliance challenges. This study assessed maternal knowledge, attitude, and compliance regarding the completion of under-five immunisation among mothers attending a hospital in Ogun State. Methods: We conducted a descriptive cross-sectional study among 122 mothers of under-five children. We used a structured, self-administered questionnaire to collect data on socio-demographic characteristics, maternal knowledge, attitude, compliance, and influencing factors. Data were analysed using SPSS version 26. Descriptive statistics and inferential tests, including chi-square and multivariable logistic regression, were performed at a significance level of p < 0.05. Results: Most respondents (30.4%) were aged 26–30 years, 78.7% were married, and 36.1% had tertiary education. Most mothers (97.5%) knew that children should receive vaccines on time, and 92.6% affirmed that immunisation starts at birth. Positive maternal attitudes were prevalent, with 81.1% agreeing that all children should be vaccinated. However, only 62.8% of mothers complied fully with their children's immunisation schedules. Key barriers included fear of side effects (35.2% reported missing or delaying vaccination), distance, waiting time, and healthcare workers' attitudes. Conclusion: Although maternal knowledge and attitude toward immunisation were generally high, compliance gaps remain due to structural and socio-cultural barriers. Strengthening health education, reducing access barriers, and improving service delivery can enhance full immunisation coverage.