Obstructive sleep apnea (OSA) and disordered breathing can be common in early development with certain conditions placing children at increased risk for OSA, such as micrognathia and the Pierre Robin sequence, craniosynostosis, and tonsillar hypertrophy. A Level 1 Sleep Study evaluation is recommended in all children with suspected sleep apnea. Part 1 of this review provides a discussion of the polysomnography study and interpretation. Part 2 focuses on diagnosis and management, emphasizing conditions that are amendable to surgical intervention and the impact of intervention on post-operative sleep study outcomes.