The Ethics Toolkit is a series within Essential Ethics designed to give clinicians a clear understanding of the tools that bioethicists use to think through complex problems. This episode looks at the Zone of Parental Discretion (ZPD) which is a protected space in which parents can make medical decisions for their children that may not be optimal (best interests) but are not substantially harmful (Harm Principle) to the interests of their child. It recognises parents as natural, and legal, decision-makers for their children and acts to preserve the parent-child-doctor relationship. Host: Prof John Massie, Clinical Director, Children’s Bioethics Centre, RCH. Guest: Prof Lynn Gillam, Academic Director, Children’s Bioethics Centre, RCH, and Professor, University of Melbourne School of Population and Global Health.