We systematically reviewed contemporary literature to create an evidence-informed framework for research studies involving children and adolescents who can assent to participate. We searched seven citation indices to locate peer-reviewed research published in English language journals between 2000 and 2012. After screening 1,231 titles and abstracts for relevance, we assessed levels of evidence, extracted information, and analysed content from 87 articles. Most articles narrowly focused on paediatric assent barriers and facilitators for decision-making about research participation. No articles provided a single, (...) comprehensive ethical framework to guide the development and review of research assent protocols. We developed a 6-step framework that provides guidance to: prepare the child for the assent process; assess the child’s readiness to engage in decision making; discuss the elements of informed consent to the greatest extent possible; seek an initial assent decision; monitor and affirm assent; and respect the child’s role as a research participant. The PAeDS-MoRe framework also supports the creation of process models that address the unique, developmental needs of paediatric sub-groups, and guides the operationalization of jurisdictional requirements for ethical research involving children who are unable to provide free, informed and ongoing consent. (shrink)