Given the diverse nature of civic and citizenship education as a “non-key” learning area with very different curricular approaches across education systems (Torney-Purta, Schwille & Amadeo, 1999; Birzea et al, 2004), the assessment of civic knowledge in ICCS 2009 had to be based on a specifically designed framework that attempted to encompass a wide range of aspects that were identified as relevant for civics and citizenship in participating countries without necessarily being reflected in each national curriculum (Schulz et al, 2008). Given its cross-national nature it was of considerable importance to ensure an appropriate level of measurement equivalence in this assessment of civic knowledge (Schulz & Fraillon, 2011). The test consisted of 80 cognitive items administered in seven rotated booklets and was used to derive the ICCS 2009 scale of civic knowledge which allows international comparisons across participating countries. Three proficiency levels were defined reflecting a hierarchy of civic knowledge in terms of increasing sophistication from knowledge of fundamental principles and broad concepts to a holistic knowledge and understanding of civics and citizenship. The paper will describe test development, procedures to ensure cross-national comparability, and selected findings for the participating European countries including some results from multi-level analyses.