The Metacognitions Questionnaire-30 (MCQ-30), developed by Wells and Cartwright-Hatton (2004), represents a multidimensional measure of metacognitive factors considered to be important in the metacognitive model of psychological disorders. The primary aim of the present study was to examine internal consistency, test-retest reliability, convergent validity and the factor structure of the Greek version of the MCQ-30. Moreover, we investigated the associations of the extracted factors with trait anxiety in a Greek sample. The study sample consisted of 547 non-clinical participants (213 males and 334 females). All participants completed the Greek version of the MCQ-30. A subsample of 157 participants also completed the Trait Anxiety subscale of the State -Trait Anxiety Inventory and the Meta-worry subscale of the Anxious Thought Inventory. Thirty participants were retested with the MCQ-30 over a retest interval ranging from three to five weeks. The results confirmed the dimensionality of the MCQ-30 and five factors were extracted consistent with the original English version: (1) positive beliefs about worry, (2) negative beliefs about worry concerning uncontrollability and danger, (3) cognitive confidence, (4) beliefs about the need to control thoughts and the negative consequences of not controlling them, and (5) cognitive selfconsciousness. The MCQ-30 showed high levels of internal consistency and test-retest reliability. The correlation between MCQ-30 total score and AnTI-MW was strong, indicating high level of convergent validity. Moreover, all correlations between MCQ-30 total and subscale scores and STAI-T were significant apart from the correlation between 'cognitive confidence' and trait anxiety. The Greek sample scored higher in the MCQ-30 and its subscales than the English sample in the original study. Women scored significantly higher than men in the overall MCQ-30 and the "uncontrollability and danger" and "need to control thoughts" subscales, whereas no significant differences between genders had been found in the original study. The assumption that the differences in score levels and the gender effect might reflect cultural differences warrants further investigation. The findings of the present study indicate that the Greek version of the MCQ-30 is a comprehensible and psychometrically adequate instrument, as well as a reliable tool in assessing a range of dimensions of worry-related metacognitions in the Greek population. The Greek version of this scale facilitates crosscultural research in metacognition and wider testing of the metacognitive approach to emotional vulnerability, psychological disturbances and mental disorders.