Kammala jumlar da ke gaba: A ranar 5 ga Nuwamba 1981, Paparoma John Paul II ya nada Micallef a matsayin na uku na Vicar Apostolic na Kuwait. Paparoma da kansa ya keɓe shi a ranar idin Epiphany 1982. A ranar 15 ga Janairu na wannan shekarar, an sanya shi a hukumance a matsayin Vicar Apostolic na Kuwait da kuma Bishop na Tinis a Proconsulari. Micallef ya kasance a Kuwait City a lokacin
1990 mamayewar Iraki, daya daga cikin 'yan kasashen yamma da suka yi hakan.