Despite the positive impact of collaborative school cultures on teachers' professional growth and student achievement, it is difficult to create such a culture. This study explores the types of school cultures in one school district in the United Arab Emirates (UAE) to identify factors that could foster or inhibit true teacher collaboration. Data consist of quantitative survey responses from 361 teachers in 24 schools, and the results of follow-up qualitative interviews with 14 teachers representing 4 schools. Results show that the most common types of school cultures were contrived collegiality and comfortable collaboration, and that true collaboration was the least common. There is also evidence that when teachers' work is governed by mandated learning outcomes, students' assessment requirements, and external accountability demands, teachers lack the time, autonomy, or willingness to create a truly collaborative work culture. The study concludes that teacher autonomy and internal accountability are key elements for creating truly collaborative cultures in UAE schools.