The constitutions and courts both in India and in Pakistan have shown their aspirations and fundamental faith in the federal structure but in practice there is a strong centripetal bias in each of their constitutional-political structures. This bias becomes more evident when the constitution sanctions power to the centre to proclaim emergency situations in the provinces on the basis of Constitutional Machinery Failure. Emerging from their colonial roots, the constitutions of India and Pakistan contain an identical provision on Constitutional Machinery Failure Emergency which has been misused and abused regularly and has been the biggest question mark on federal claims of the two States. This unique system of Constitutional Machinery Failure Emergency has also gone through a number of radical changes in India and Pakistan, which often have been influenced by each other. The article specifies the socio-political-constitutional background of Constitutional Machinery Failure resulting in Provincial Emergency, both in India and in Pakistan, their respective use and abuse by the Executive, legislative attempts to amend and control such power, and judicial response, with similarities and differences in respect of justifiability of such Emergency Proclamations.