Background Writing directly to patients or copying letters to them is common practice in Child and Adolescent Mental Health Services (CAMHS). If the intention is to increase young people's understanding and collaboration in their health care, then the readability of such letters is important. The aim of this study was to reassess the readability of letters sent to patients from the Young People's Department at Royal Cornhill Hospital since it adopted the choice and partnership approach (CAPA). Method Readability of clinical letters was measured using indices available in Microsoft Word. Results were compared to readability thresholds. Results Most letters sent to patients were still not easily readable. Conclusions Awareness of easily accessible readability formulae has not led to acceptable levels of readability in letters. More needs to be done to investigate patients’ views and improve communication.