The ability of psychiatric patients and prisoners to provide informed consent to participate in clinical research has given rise to much debate. Forensic psychiatric patients present a particular concern regarding their competence to consent to research, as they are both patients and prisoners. The primary goal of this research was to evaluate whether, by employing structured assessments of capacity to consent to research, we could determine if this combined vulnerability leads to differences in competence from the published abilities of nonforensic psychiatric patients. Subjects deemed incapable of providing informed consent scored differently and lower than the other consent groups on three aspects of the decision-making process. Diagnosis evidenced only a slight relationship to decision-making abilities, and this difference was only in the ability to understand the basic procedural elements of the research. Psychiatric symptoms were modestly related to decision-making. Positive symptoms were associated with poorer performance on the Understanding subscale of the MacCAT-CR, and negative symptoms were associated with lowered performance on the Reasoning subscale. These results are in accord with several published studies of nonforensic psychiatric patients and suggest that concerns regarding both forensic and nonforensic psychiatric patients' ability to provide informed consent may be unwarranted, especially in patients with few active symptoms.