An important empirical question is whether the Cultural Mistrust Inventory (CMI) can be used to measure cultural aspects of paranoia in Black psychiatric populations. Research on cultural mistrust in psychiatric populations is essential for tests of hypotheses regarding the misdiagnosis of African Americans. The purpose of this study was to assess the reliability and validity of the CMI in a sample of African American patients recently admitted to a psychiatric hospital. The reliability assessment revealed that the CMI total scale is a reliable measure. Factor analytic results indicated that a single global dimension underlies CMI scores. The CMI also showed good convergent validity with a measure of nonclinical paranoia and discriminant validity with measures of self-esteem and social desirability. This study provides reasonable evidence that use of the CMI with psychiatric patients is psychometrically sound. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 383–396, 2002.