Although research has highlighted the importance of teachers' influence on school-wide policies, less attention has been given to the role of the influence of teachers relative to the principal within a school. This study thus examined the extent to which the influence of teachers relative to the principal in school decision-making predicts teachers' job attitudes, i.e. job satisfaction and professional commitment. By using the National Teacher and Principal Survey 2015-2016, nationally representative data from 19,450 teachers and 2,860 principals of public schools in the United States were analysed. The findings revealed the greater the relative influence of teachers, the more positive the association with teacher job satisfaction and professional commitment as job attitudes. The current study showed that the extent of teacher influence relative to that of the principal plays a critical role in social conditions within a school and can improve individual teachers' job attitudes regarding school decision-making.