During all this ferment of missionary activity, Eugene was an outstanding pastor of the Church of Marseilles-ensuring the best seminary training for his priests, establishing new parishes, building the city's cathedral and the spectacular Shrine of Notre Dame de la Garde above the city, encouraging his priests to lives of holiness, introducing many Religious Congregations to work in the diocese, leading his fellow Bishops in support of the rights of the Pope.
Bien qu'il ait fondé les Oblats de Marie Immaculée pour apporter d'abord les services de la foi aux pauvres des campagnes de France, le zèle d'Eugène pour le Royaume de Dieu et son amour pour l'Église amenèrent les Oblats à la pointe de l'apostolat missionnaire. Ceux-ci s'installèrent en Suisse, en Angleterre et en Irlande.