Objectives <p>This study aimed to translate, culturally adapt, and validate the Chinese version of the Interpersonal Mindfulness Scale (IMS-CV) using both Classical Test Theory (CTT) and Item Response Theory (IRT).</p> Methods <p>A total of 938 Chinese undergraduate students completed the IMS-CV and measures of trait mindfulness, personality traits, and emotional intelligence. CTT was used for item analysis and validation (content validity, construct validity, and criterion validity) and reliability (internal consistency, test–retest reliability). IRT was applied to assess item-level discrimination and difficulty parameters.</p> Results <p>Confirmatory factor analysis (CFA) supported the original four-factor structure, and the bifactor model supported a strong general interpersonal mindfulness factor. The IMS-CV showed high internal consistency (Cronbach’s <i>α</i> = 0.93, McDonald’s <i>ω</i> = 0.92) and test–retest reliability (ICC = 0.99). It was positively associated with trait mindfulness, agreeableness, extraversion, and emotional intelligence, and negatively with neuroticism, supporting criterion validity. IRT analyses showed high discrimination (<i>a</i> &gt; 1.75) and a broad difficulty range (<i>b</i> ≈ − 3.60 to + 1.80). Measurement invariance across gender indicated configural, metric, and scalar equivalence.</p> Conclusions <p>The IMS-CV demonstrates robust psychometric properties and strong structural validity, supporting both subscale and general factor interpretations. It provides a reliable tool for assessing interpersonal mindfulness among Chinese undergraduates and facilitates cross-cultural research in non-Western contexts.</p> Preregistration <p>This study is not preregistered.</p>