Environmental issues know no boundaries and are recognised as a matter of regional and/or global concern, and neighbouring countries have to face shared environmental effects. Environmental laws internationally, particularly in the last thirty years, have grown significantly and have contributed to environmental protection in a variety of national, regional and international management strategies. In recent years, environmental legislation has entered into a responsible and mature phase in several non-Western countries, particularly in Asia. The present study examines the shared environmental obligations of regional or neighbouring countries using China and Pakistan as a case study and provides references from international (environmental) laws as well as states’ best practices. This study adopts a well-defined analytical methodology to not only investigate the implications of environmental laws but also to define the gaps in the existing framework of environmental laws in the region and recommend appropriate grounds to systematically fill these gaps through much-needed legal cooperation before it is too late. The study provides a detailed analysis and pertinent knowledge horizons, and concludes that there is an abrupt need for China and Pakistan to revise their trade agreements and include the environment as an integral part of each mega-infrastructural activity, including the China-Pakistan Economic Corridor. Most of the potential outcomes are already known but there is little academic discussion available concerning the perspective of cross-boundary environmental laws, and the present study intends to fill this gap.