With growth of civilizations the insatiable demand for water resources has increased manifold. This huge stress on water resources due to increasing demands and declining water levels, growing vulnerability from floods and droughts, and eco-hydrological problems confront water resources management with challenges that need comprehensive strategies for providing water of adequate quantity and protecting mankind from adverse impacts. Sustainable solutions for trans-boundary water aquifer systems are therefore of high priority since nature does not draw its boundaries to coincide with the political boundaries. Punjab state is one of the most prosperous states of India with an agricultural based economy. The total water requirement of the state is 61.675 billion cubic meter (BCM). Against this, the water availability is only 17.54 BCM of surface water and 23.78 BCM of replenishable ground water resources. Punjab has a very long international boundary and the ground water aquifers are contiguous across the border too. Whereas the majority of the recharge areas lie in the hills of J&K and Punjab, the discharge areas extend to Pakistan too. It is thus felt that now is the time to study the trans-boundary aquifers of Punjab state in totality and on the basis of proper assessment of ground water contained down to a certain depth (say 1000 meters), decide the allocation of ground water usage by the neighbouring countries. The present paper outlines the above along with the ydrogeological set up of Punjab state with special emphasis on Upper Bari Doab area covering the districts of Amritsar, Gurdaspur and Taran Taran. Towards the end of the paper, a case study of trans-boundary aquifers across two states, Haryana and Uttar Pradesh, within India has also been detailed. The main aim of this was to study the effect of pumping of ground water through augmentation tubewells in Haryana on the Yamuna river flows and ground water resources of adjoining state of Uttar Pradesh. Similar situation may be present across global trans-boundary aquifers also. This study is a case in point to prove that study of trans-boundary aquifers is the need of the day.