In 1751, he founded the town of Najibabad in Bijnor district, India, after he received the title, "Najib-ud-Daula" from Mughal Emperor Alalmgir III.

Many architectural relics of the period of Rohilla he oversaw remain in Najibabad, which he founded at the height of his career as a Mughal minister.

According to George Foster ("A Journey from Bengal to England", 1790): Najibuddaulah, who built this town, saw that its situation would facilitate the commerce of Kashmir, which having been diverted from its former channel of Lahore and Delhi, by the inroads of Sicques [Sikhs], Maharattas and Afgans, took course through the mountains at the head of the Punjab and was introduced into the Rohilla (country) through the Lall Dong Pass.

This inducement, with the desire of establishing a mart for the Hindoos of the adjacent mountains, probably influenced the choice of this spot, which otherwise is not favourable for the site of a capital town being low, and surrounded by swampy grounds….

since the death of its founder, Najibabad had fallen from its former importance and seems now chiefly upheld by the languishing trade of Kashmir.