This study uses a cohort model--a combination of a study group, with readings and discussion, and collaborative curriculum design as a professional development tool--as a context for investigating a group of middle and high school world language teachers' beliefs about effective curriculum. The study explores whether this model could shift teachers' beliefs positively regarding world language curriculum, moving from more traditional grammar-based curricular models toward a communicative approach. Previous research has documented the importance of teacher beliefs in education and how different professional development models impact them. However, this study is novel in using curriculum design as the focus of professional development within the context of world language education. Teachers' beliefs about communicative curriculum were surveyed before, during, and after participation in the cohort to ascertain if a shift in their beliefs occurred as a result of involvement in the study. Using a series of three surveys collecting both quantitative and qualitative data, results indicate a positive shift in teacher beliefs about the value of a communicative curriculum, their own abilities in implementing this type of curriculum, students' anticipated success with the curriculum, and the effectiveness of the cohort model. This model could be replicated in similar districts to effect change in teacher beliefs while developing the capacity for world language curricular revision.