Developmental delay is common and is often associated with long term problems in learning, behaviour and mental health. Early intervention before three years of age is crucial for improving long-term outcomes. With the rising prevalence of child developmental problems in Singapore, primary care physicians as part of a child developmental surveillance program, are well placed to identify children with developmental delays early and refer for further evaluation. Developmental surveillance is recommended at every well-child visit. Parents play an important role in their child's development and can monitor the development by completing the developmental checklists in the health booklet. This article aims to outline an approach to child development surveillance and screening for children 18 months to four years old in primary practice and accompanies the guidelines on Child Development Screening (CDS) developed by the Ministry of Health.