People admitted to medium secure psychiatric care are recognised to still be at risk of experiencing adverse outcomes upon discharge. However, little is known about the outcomes of patients admitted more recently to medium secure care or the long-term outcomes of people many years after discharge. The aim of this study was to assess the mortality, conviction and readmission outcomes of a cohort of first admissions discharged from an English medium secure psychiatric unit between July 1983 and June 2013. Data on background characteristics were obtained from medical records. Outcome data were obtained from multiple sources for 843 patients discharged prior to the census date of 30 June 2013. The risk of death from both natural and unnatural causes was much higher than that of the general population. Of those patients that were discharged, 369 patients (43.8%) were convicted of an offence during the follow-up period, two-thirds of which were convicted within the first 5 years following discharge. Five hundred and ten patients (61.6%) were readmitted to psychiatric care. Patients discharged from medium secure care are at long-term risk of experiencing premature death, conviction and readmission to secure and non-secure psychiatric care.