His uncle Daniel Jr. was House Speaker from 1956 to 1962 while his grandfather Miguel served as Manila mayor during the American colonial period and Leyte assemblyman during the Commonwealth Era.
He was the eldest of the seven children of Alberto Zialcita Romualdez Sr., a former secretary general of the World Medical Association, and Covadonga del Gallego, a former chairman of the Pathology Department of the University of Santo Tomas Hospital.