Psychological mindedness (PM) refers to a person's interest and ability to be in touch with and reflect on his or her psychological states and processes. In this multipart study, the authors present the Balanced Index of Psychological Mindedness (BIPM). The psychometric properties and clinical relevance of this 14-item self-report scale were examined in 2 community samples and a mental health patient sample in the Netherlands (total N = 1,211). The 7-item Interest and Insight subscales of the BIPM showed good internal consistency (Cronbach's alphas = .85 and .76, respectively), test-retest reliability (r = .63 and .71, respectively), and construct validity (e.g., r > .40 with related constructs). PM was higher in women than in men. Relatively low PM was found among poorly educated people and in mental health patients (ps < .001). Insight, but not Interest, correlated negatively with symptoms of psychological distress (r = -.21 to -.36, p < .05) for 6 out of 8 symptom scales in mental health patients. These data suggest that the BIPM is a concise, valid, and clinically relevant self-report scale that may enhance research on PM in clinical groups as well as the general population. (PsycINFO Database Record (c) 2009 APA, all rights reserved).