The psychodiagnostic interview is an essential component of mental health diagnosis in which mental health professionals collect specific information about an individual to label his or her mental health problems. A significant number of individuals involved in the criminal justice system have been diagnosed with a mental disorder. Many more may have undiagnosed problems. Misdiagnosed or undiagnosed problems pose a serious barrier to the rehabilitation of offenders as [Page 1138]accurate diagnosis is an important early step to effective treatment. There is ongoing concern that untreated mental disorders may lead to violence or reoffense. This entry introduces readers to the goals of psychodiagnostic interviewing, offers examples of different approaches to interviewing, and provides a brief overview of the key content covered in a typical interview.