The Inventory of Interpersonal Problems (IIP32) is a self-report measure designed to be used in clinical settings to assess interpersonal difficulties. However, it has been exclusively used in either outpatient or non-clinical settings, and psychometric data concerning its use in inpatients are limited. The current study examined the factor structure and construct validity of the IIP-32, and ways to optimally use this measure with inpatients at a private hospital providing intensive treatment. The original eight-factor structure was a poor fit to the data, whereas a five-factor structure provided a somewhat better fit. Although the five factors (Nonassertive, Detached, Intrusive, Self-Sacrificing, and Socially Inhibited) demonstrated adequate internal consistency, reliability, and limited convergent validity, the IIP is ultimately useful insofar as it engages patients in collaborative self-awareness during intensive psychotherapeutically oriented treatment.