To examine the utilisation of the insanity defence in Queensland and insanity acquittee reoffending, offences cleared by the police were compared with charges heard by the Mental Health Tribunal (MHT) and appearances before the MHT from 1985 to 2002 were cross-linked with police databases. Only 0.24% of cleared offences were heard by the MHT. This plea rate was similar to that in the US jurisdictions where the insanity defence has been extensively researched. Overall, persons not afforded an insanity defence reoffended more frequently, committed more offences, including more violent offences, and committed more serious offences as measured by the National Offence Index. Furthermore, offending occurred sooner than that of insanity acquittees. Evidence was not found for ''over-use'' of the insanity defence and overall, recidivism was lower and less serious for insanity acquittees. There is a need for further research to more comprehensively identify factors associated with positive outcomes.