During the operations against Pakistan in December, 1971, Squadron Leader Ujjal Singh Pruthi was serving as a surgical specialist in on Air Force Hospital in the Eastern Sector. It was entirely due to his foresight and planning that the hospital could meet all demands placed on it. With his professional knowledge and administrative ability, he stepped up the hospital to a high state of efficiency. As the battle casualties started pouring in, he singlehanded carried out surgical operations for long periods. On one occasion, 41 casualties were attended to and emergency operations carried out in a period of 48 hours. On another occasion, when 22 casualties were brought in, he worked in the Operation Theatre for 36 hours at a stretch. The hospital treated 148 battle casualties during a period of ten days. As a result of prompt attention, all the cases were saved without losing a single life.

Throughout, Squadron Leader Ujjal Singh Pruthi displayed professional skill and devotion to duty.