[4] In the 1970s, Marcos headed a defense fund which supported two Filipina nurses accused of killing 10 patients in the Ann Arbor Hospital Murders.

[5] He owned, controlled, or had interests in 50 corporations,[6] including a large car dealership,[3] a sugar mill called Consolidate Sugar Corporation,[7] a real estate firm called Citizens Development Inc,[8] and Philippine Seed Inc.[9] Marcos did not involve himself in politics, and distanced himself from his brother's regime when it grew unpopular during the 1980s.

In 1998 Marcos was the subject of a lawsuit over an under-collateralized behest loan in the amount of ₱60 million which his company, Bagumbayan Corp, received from the Development Bank of the Philippines.

[10] The case was finally dismissed in 2007 by the Supreme Court, which said there was no evidence that the loan was given simply because Pacifico Marcos was a "crony" of the former president.

[11] His son, Mariano "Nonong" Marcos II, who became a provincial board member in Ilocos Norte,[12] died on February 15, 2019.