From 1971 to 1975, he served as Secretary-General of the Southeast Asian Regional Branch of the International Council of Archives (SARBICA).
He was also an elected member of the Rome-based Advisory Council of the International Center of the Study of the Conservation and Restoration of Cultural Property (ICCROM).
He is a former member of the Ad-Hoc Numismatic Committee of the Central Bank of the Philippines, the UNESCO Advisory Committee for the Study of Malay and Southeast Asian Cultures in 1978, a former Trustee of the Museo ng Malacanan Foundation from 1986 to 1990, a member of the Silk Road Expedition Across Central Asia which was sponsored by UNESCO Paris in 1990, a member of the National Centennial Commission from 1993- 1998, a former regent of the Pamantasan ng Lungsod ng Maynila from January–June 1998, a Project Director of the Museo ng Maynila in 1997-1998 and a Consultant to the Lopez Museum & Library.
He is also instrumental in the construction and completion of the Museum of Philippine History and National Historical Building at Rizal Park.
He was conferred the Lifetime Achievement Award by University of the Philippines Alumni Association in June 2009, the Outstanding Citizen of Quezon City in November 2009, and Outstanding Lifetime Achievement Award by the University of the Philippines Alumni Association in 2015.