 On 14 May 2005, Alfano was appointed Archbishop of Sant'Angelo dei Lombardi-Conza-Nusco-Bisaccia.He was consecrated a bishop on 2 July 2005 by Bishop Gioacchino Illiano and co-consecrators Archbishop Paolo Romeo and Archbishop Salvatore Nunnari.On 10 March 2012, he was appointed Archbishop of Sorrento-Catellammare di Stabia, but continued to serve as apostolic administrator of the Archdiocese of Sant'Angelo dei Lombardi-Conza-Nusco-Bisaccia until 6 January 2013.