ntroduction: The child health record book was long established in Malaysia, but no evaluation study on the util-isation of the book has ever been done. The objectives of the study were to determine the proportion of optimum record book use and the factors associated with it. Methods: A cross-sectional study was conducted among 415 ran-domly selected parents of children aged below six years old attending government health clinics in Putrajaya using a self-administered questionnaire. Optimum use of child health record book was defined by respondents reading all the sections and recording comments in the book. Factors studied were sociodemographic characteristics; ante-natal and breastfeeding history; child’s health and immunisation status; perceptions and level of knowledge on the book and child health; and healthcare providers’ performance. Multiple logistic regression was used to identify the determinants of optimum use. Results: In total, 36.1% of respondents optimally used the record book. The five de-terminants of optimum use identified were mother’s age group between 35-39 years and ≥40 years old (AOR: 2.24, 95% CI 1.13-4.44; AOR: 3.36, 95% CI 1.24-9.07), a mother with a higher level of education (AOR: 2.67, 95% CI 1.43-5.00), delivered in a government hospital (AOR: 3.01, 95% CI 1.11-8.16), had good level of knowledge on the record book and on general child health (AOR: 3.69, 95% CI 2.08-6.56; AOR: 2.07, 95% CI 1.19-3.60). Conclusion: The proportion of optimum child health record book use is relatively low. Based on the findings, improving the par-ents’ knowledge on the child health record book utilisation is vital to increase the optimum usage particularly among mothers with low education level, aged less than 30 years old and those who delivered in non-government hospitals.