This chapter outlines the evolution of this mix of environmental policy instruments, including regulatory, economic and information-based measures. Portugal’s extensive system of environmental enforcement and compliance promotion is examined, along with the efforts made in promoting public participation in environmental decision-making and opening up access to information and justice. Progress has been noted in the improvement of air quality, particularly in urban areas, reducing pressures on inland and coastal waters, strengthening the management of water supply and sanitation systems, and improving waste management efforts, including the reduction, appropriate treatment, and safe disposal of hazardous waste.