Research demonstrates that mental health courts (MHCs) lead to improved outcomes compared to traditional criminal court processes. An underlying premise of MHCs is therapeutic jurisprudence (TJ). However, no research, to our knowledge, has examined whether MHC outcomes are predicted by TJ principles as theorized. In the present study, we examined whether principles measured at the onset of MHC enrollment (knowledge, perceived voluntariness, and procedural justice) predicted MHC completion (graduation). Using structural equation modeling with MHC participants from four courts, a significant, direct relationship between TJ and MHC completion was found, such that higher levels of TJ were associated with higher rates of success. Although this direct effect became nonsignificant when mediator variables were included, a significant indirect path remained, such that increased levels of initial perceived voluntariness and procedural justice, and MHC knowledge, led to decreased rates of new arrests, prison, MHC bench warrants, and increased court compliance, which, in turn, led to a higher likelihood of MHC graduation.