 Pope Paul VI appointed him auxiliary bishop of Quito in 1969, and in 1975 he was transferred to the diocese of Ibarra.In 1983, Pope John Paul II appointed him the first military bishop of Ecuador and in 1988 he moved him to Guayaquil, where he served as Archbishop from 1989.John Paul II accepted Holguín's resignation from episcopal duties in 2003, when Holguín was aged 75.