Behavioural and Socio-emotional Disorders are often overlooked in developmental screening as there is a wide range of what appears normal in the preschool age. Au-tism spectrum disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) of preschool onset are the most commonly occurring disorders which may present to the primary care physician. There is a wide range of what is ‘normal’ in children’s behaviours and socio-emotional development which a primary care physician can expect to meet during each of the six well-child visits. Typical behaviours and learning at each developmental stage and what the physician can address at each of the ‘well-child’ visits will be reviewed. The screening to be conducted at each visit will follow on from ‘red flags’ described in the Singapore Child Health Booklet.