A comparative analysis of psychotic versus nonpsychotic stalking is presented. Archival files of 25 forensic subjects whose alleged criminal offenses met a legal definition of stalking behavior were studied for demographic characteristics, stalking dynamics, psychosocial history, and current psychological variables. Although nearly one-third of all subjects had an Axis I psychotic disorder and were delusional, only one of these subjects had erotomanic delusions. The psychotic subjects' pursuit of victims was associated with other delusions and symptoms of psychosis. Nonpsychotic subjects tended to exhibit an Axis I disorder (usually major depression, adjustment disorder, or substance dependence) as well as a variety of Axis II personality disorders. The nonpsychotic subjects' pursuit of victims was influenced by various psychological factors, including anger and hostility, projection of blame, obsession, dependency, minimization and denial, and jealousy. Psychotic subjects visited the victims' homes significantly more often than nonpsychotic subjects. Nonpsychotic subjects made more verbal threats and "acted out" violently more often than psychotic subjects. While all subjects exhibited some similarities in stalking behaviors and demographic variables, including childhood attachment disruptions, no single profile of a "stalker" emerged. These findings provide information about factors contributing to stalking violence, as well as diagnostic issues that should be considered in the assessment and treatment of this criminal population.