Past research has documented the relevance principals have for school improvement. However, how principals lead schools is dependent on institutional context. Furthermore, an international comparison of leadership might be susceptible to bias because the majority of leadership research is from Anglophone countries. The goal of the paper was to test whether constructs of "effective" leadership in international research are applicable to leadership practice in two contrasting institutional environments (United States and Germany). In both countries, teachers completed a leadership survey. Differences between the samples were analyzed utilizing Rasch analysis to evaluate potential differential item functioning. This was done to investigate differences in the way that items were viewed to define the construct as a function of sample. The findings indicate that leadership practices related to effectiveness and performativity were less pronounced in the German schools as opposed to the US schools, and leadership practices related to collaboration and participation were more pronounced.