In this chapter, we discuss the issue of accountability and its effects on teaching and learning. We examine different forms of accountability, and take the stance that accountability can improve learning outcomes if accompanied by curriculum support rather than financial penalties. We draw example data from a range of national and systemic high-stakes testing programs and the effects on achievement levels over time. We consider contrasting effects of formative and summative roles of assessment within a context of accountability frameworks. This is not to question the role of accountability, but to assess ways in which the potential damaging effects can be reduced and student performance can be identified, validated and enhanced.