Criminal defendants found incompetent to stand trial (IST) are sent to state hospitals for treatment to be restored to competency. IST patients diagnosed with dementia and related disorders present a particular challenge to clinicians, because they must be restored successfully within a statutorily mandated time frame (e.g., 3 years in California for defendants charged with a felony offense). This study examined a comprehensive data set that included all forensic patients served by California's Department of State Hospitals from September 2003 to February 2016. The findings revealed that, although most IST patients with a dementia diagnosis were restored to competency within the statutory time frames, they spent, on average, over twice as long confined than IST patients without a dementia diagnosis and were less likely than the latter group to be successfully restored. One implication of these findings is that forensic clinicians ought to assess whether IST patients diagnosed with dementia are likely to be restored or not as early as possible in the evaluation and triage process and report to the court any IST patients with a dementia diagnosis who are unlikely to be restored successfully. This would both prevent such patients from gratuitous confinement as well as free up treatment resources for other patients.