We proposed a relationship between territoriality and obsessive-compulsive (OC) symptoms and derived and tested several hypotheses. We predicted that territoriality could be adequately assessed by a new self-report measure, that a nonspurious and significant relationship exists between territoriality and OC symptoms and disorder, that territoriality would serve as a risk for the future increase of OC symptoms, and that OC disorder (OCD) patients would manifest their territoriality needs by choosing to sit farther from their therapists than non-OCD patients. Results from four studies on nonpatient and patient samples were consistent with our preliminary conceptualization, which deserves continued development and research attention. (C) 2001 Elsevier Science Inc. All tights reserved.