Cognitive development in children begins with brain development. Early life exposures may both positively and negatively influence cognitive development in children. Infants, toddlers, and children learn best in secure, nurturing environments and when attachment to a consistent caregiver is present. Pediatricians can screen for both social determinants of health and developmental milestones at office visits to address barriers to care and promote positive cognitive and learning outcomes. Pediatricians may model developmental stimulation during office visits to talk with an infant/child, asking questions of a child, singing and pointing to pictures in books, and modeling responsive listening. Pediatricians may support caregivers to talk with their children, read to their children, and avoid/reduce screen time. Pediatricians can help point caregivers to resources for parent training, Head Start, and quality preschool programs. School readiness has both pre-academic and socioemotional components and can have long-term effects on a child’s school success, health, and quality of life. School readiness depends on both the child and the caregiver being ready for school, taking into account caregiver and child health and mental health and child cognitive development.