Three studies examined if teachers' belief about writing predicted their efficacy to teach writing. We surveyed primary grade teachers from Taiwan (N = 782), Shanghai (N = 429), and the United States (N = 214). At each location, teachers completed surveys assessing their attitudes toward their own writing and the teaching of writing, beliefs about their students’ progress as writers, and epistemological beliefs about writing instruction, writing development, and writing knowledge. We examined if each of these beliefs made unique and statistically significant contributions to predicting efficacy to teach writing after variance due to all other predictors as well as personal and contextual variables were first controlled. With one exception, these three sets of beliefs each accounted for unique variance in predicting teacher efficacy at each location. There was, however, variability in unique variance in teacher efficacy scores accounted for by specific beliefs across locations and the factor structure of various measures by location.