This study examined whether the presence of a comorbid substance use disorder increased the risk of criminal recidivism and reincarceration in prison inmates with a severe mental illness. Our analyses of more than 61,000 Texas prison inmates showed that those with a co-occurring psychiatric and substance use disorder exhibited a substantially higher risk of multiple incarcerations over a 6-year period compared to inmates with psychiatric disorders alone or substance use disorders alone. Further research is needed to identify the factors associated with criminal recidivism among released prisoners with co-occurring disorders.