Dr Lee had been with the bank since 1946 and held a number of key roles thereafter, including as advisor to the founding chairman S H Ho and other board members. He became director of the bank in 1960 and in 1983 was named executive chairman. He retired in 1998 and was made honorary chairman, after which he became honorary senior advisor to the bank.
The company credits Dr Lee for his instrumental role in turning Hang Seng into one of the largest lenders in Hong Kong and helping prevent a bank run in 1965 by injecting capital from Hong Kong & Shanghai Banking Corporation. He was also part of the team that built the Hang Seng Index.
According to a statement by current chairman Raymond Ch'ien, Lee was a driving force in the bank's education initiatives, including the founding of the Hang Seng School of Commerce and the establishment of the Ho Leung Ho Lee Foundation, which notes scientific and technological achievements. In another statement by Rose Lee, vice-chairman and chief executive, he is described as a "man of highest integrity" with a remarkable record of public sector and philanthropic work.