Health professionals frequently write at the same level for lay readers as they write for peers. In relation to health research and ethical requirements to provide written explanation of studies, this can complicate the notion of informed consent. Plain language information statements need to be clearly understood by research subjects if the ethics process for research approval is to fulfil its objective. Many delays in gaining ethics approval for child-related research are caused by substandard plain language statements (PLS). We describe specific issues for information statements for research with children, young people and their parents/guardians, particularly in consideration of the literacy capabilities of the general population. We highlight the usefulness of everyday language when explaining research and science in writing to families, and present some guidelines for writing PLS that have emerged from the introduction of a plain language service by an Ethics in Human Research Committee.