Educational scholars claim that teacher morale has suffered from accountability pressures and constrained professionalism, but exactly what is most diminished by these pressures remains unclear. Drawing on recent theoretical work on public school organizational culture, we hypothesize that accountability pressures hurt teacher morale and increase the risk of turnover by undermining the professional culture of the school and by diminishing teacher cooperation and trust. We find support for this hypothesis in a national sample of teachers in 2011-12, and a follow-up survey from 2012-13. The analyses test whether a collective pedagogical teacher culture, comprised of professional culture and teacher collaboration, buffers the impact of these pressures that diminish teacher morale. Counter to past research, we find that a strong collective pedagogical teacher culture does not buffer teachers from the ill effects of negative workplace conditions in the form of accountability pressures. We also find that accountability pressures in the form of district dismissals are associated with a higher likelihood of teachers leaving their school, and this relationship is not mitigated by strong professional culture. We conclude that accountability pressures partly undermine goals of improving performance and equity in public schools by sowing seeds of teacher dissatisfaction and contributing to teacher turnover, thus thwarting student achievement in struggling schools.