We investigated the quality of 100 discharge letters from mental health specialists to better understand the role of cross-sectoral communication in patients’ readmissions or other unplanned recontacts with mental health specialist care. Using a case-control design, we compared 50 letters for patients readmitted or for whom a formal request for additional specialist mental healthcare was made by the patient’s GP (recontact) within 30 days of discharge, and 50 letters for those without readmission or recontact. The 26-item checklist Quality of Discharge letters – Mental Health was used to assess discharge letter quality. No significant differences in total checklist scores were found, suggesting that discharge letter quality does not influence the rates of readmission or unplanned recontact in mental healthcare.