Background: Premature neonates are a high-risk group of developmental problems. Improvements in technology in the Neonatal Intensive Care Unit (NICU) have led to improved survival of preterm neonates. This study was aimed to evaluate the growth, development, behavioral, immunization completion and long-term outcome of preterm infants. Methods: A cohort study of preterm infant’s post-discharged from NICU of Dr. Cipto Mangunkusumo National Central Public Hospital (CMNCPH) will be done at Developmental Behavioral – Community Pediatrics (DB-CP) clinic of CMNCPH. Developmental screening and assessment using the Ages and Stages Questionnaire 3rd edition and Bayley Scales of Infant and Toddler Development 3rd edition (BSID-3) will be performed at the corrected age of age 9-12 months, 18-24 months, 30-36 months, and 48-54 months. Screening for autism spectrum disorders (ASD) and attention deficit hyperactivity disorders (ADHD) will be performed at 18-24 month and 36 months of age respectively. Discussion: Our study is a prospective cohort study focusing on growth, development, behavioral, immunization completion and long-term outcome of preterm infants. With a follow up until 54 months, this study may provide early detection, early diagnosis, and early intervention of growth, developmental and behavioral impairment and ensuring the optimum outcomes and quality of life for surviving neonates.