Purpose: The study investigates the voice behavior of teachers and headteachers in Kuwaiti schools, along with organizational factors associated with teachers' voice behavior. Design/methodology/approach: The study employed a convergent mixed-method approach. Questionnaires were administered to a sample of 815 teachers and headteachers, with 28 of them participating in open-ended interviews. Findings: In quantitative findings, high levels of prosocial voices were observed, while interviews revealed significant occurrences of defensive and acquiescent voice behaviors. Teachers practice prosocial voice behavior to protect students' interests, but various factors, such as individual characteristics, school leadership, hierarchy and governmental decisions at the district levels, influence their voices. Originality/value: The findings enhance our understanding of voice behavior among teachers and headteachers, shedding light on the factors influencing voice behavior in Kuwait and centralized systems worldwide.