Environmental impact assessment (EIA) is a process that involves the identification, prediction, evaluation and mitigation of the environmental and other impacts associated with development proposals and policies, plans and programs. Australian governments were amongst the first in the world to introduce EIA in the 1970s. Since then, the federal, state and territory EIA regimes have undergone multiple changes. In recent times, the push for EIA reform has intensified as governments have sought ways to improve the cost-effectiveness of regulatory processes. In light of the impetus for change, this article outlines principles and a framework for best practice EIA in Australia. The intention is to inform the policy development processes at the federal, state and local levels.