The pressures of economic development on society and environment in Asia have resulted in national sustainability policy responses in two countries, Thailand and Bhutan, that derive from a traditional Buddhist approach but which have been modernized in the light of the contemporary global challenges that these Asian nations face. Referred to as Sufficiency Economy in Thailand and Gross National Happiness in Bhutan, these responses have been adopted because of the pressures of development and associated environmental and social costs. The Sufficiency Economy and Gross National Happiness approaches have been shaped to assist in the formulation and implementation of ethically sound policies to protect the environment, society, and individuals – in line with traditional Buddhist spiritual, ethical, and cultural teachings. This chapter examines examples of how Sufficiency Economy and Gross National Happiness have been realized. Aspects of Thailand’s process of implementing Sufficiency Economy and Bhutan’s adoption of Gross National Happiness are discussed via two empirical case examples: Local Agenda 21/Local Action 21 projects in Thailand in 2000–2003, and the implementation of energy and environmental policy projects in Bhutan. It is concluded that the furtherance of these contemporary sustainability approaches sourced from Buddhist principles is very important for the future of these nations.