Item translations of all used questionnaires.

<div><p>Introduction</p><p>Parental Reflective Functioning describes the parents’ ability to view their child as motivated by mental states. The Parental Reflective Functioning Questionnaire (PRFQ) represents an 18-item and three-factor self-report measure. Our goal was to conduct the first German validation study.</p><p>Method</p><p>In a community sample of 378 mothers of children aged 10.2–78.6 months, we used Confirmatory Factor Analysis with a cross-validation approach to assess model fit. Reliability was measured using Cronbach’s <i>α</i> and McDonald’s <i>ω</i>. Concurrent validity was assessed using correlations with relevant constructs.</p><p>Results</p><p>The three-factor structure of the original validation could be confirmed. The German model only needed minor modifications: two items had to be removed, and one error covariance was added. The resulting 16-item questionnaire with the three subscales “Pre-mentalizing”, “Interest and Curiosity about Mental States”, and “Certainty about Mental States” was successfully cross-validated (CFI = .94, TLI = .93, SRMR = .07, RMSEA = .04 (CI [.01, .06])). These factors were related in theoretically expected ways to parental attachment dimensions, emotional availability, parenting stress, and infant attachment status.</p><p>Conclusion</p><p>While reliability could still be improved, the German 16-item version of the PRFQ represents a valid measure of parental reflective functioning.</p></div>