Environment and sustainable development is the focus of Nepal for its sustainability. There is deepening crisis in environment and sustainable development in Nepal, which made significant crisis on socio-economic, socio-culture, socio-environment and socio-institutional development of the country. It was because of lack of vision on comprehensive environment and sustainable development of the country. Unstable government, loot political culture, rampant corruption, extreme level of violations of human rights, state impunity, failed governance, absence of state, global warming and climate change and its direct impacts on people of Nepal and its environmental zones were the main causes for the crisis. With the diagnosis of chronic level of crisis in the country, the book tries to construct a theory on "Comprehensive Approach for Environment and Sustainable Development" for Nepal as a capsule for its sustainability finally. So, there could be resolved the crisis of environment and sustainable development of Nepal through applying the theory of "Comprehensive Approach for Environment and Sustainable Development".