The species was collected by Hugh Low on Mount Kinabalu in 1858, and described the next year by Joseph Dalton Hooker, who named it after James Brooke, the first White Rajah of Sarawak. Hooker called it one of the most striking vegetable productions hither-to discovered. Since being introduced into cultivation in 1881, Nepenthes rajah has always been a much sought-after species. For a long time, the plant was seldom seen in private collections due to its rarity, price, and specialised growing requirements. However, recent advances in tissue culture technology have resulted in prices falling dramatically, and N. rajah is now relatively widespread in cultivation.