The aim of this study, conducted at Nitichitawej Hospital (Hospital for the Forensic Psychiatric Services), Bangkok, Thailand, is to analyse the readmission rate of mentally ill male offenders who had been transferred to this hospital for assessment, treatment or detention from 1972 to 1986. Nitichitawej Hospital deals with forensic cases referred from police, courts, prosecutors and prisons from all over Thailand. Of the total of 2112 cases admitted during the sample period, there is evidence of only 22 cases being readmitted. The characteristics of this readmission group is considered and the reasons for this remarkably low readmission figure of around 1% are assessed.