The patron of Acquaviva d'Isernia is Saint Anastasius, celebrated on 22 January, to whom the Chiesa di Sant'Anastasio Martire is dedicated.
On the eve, the evening of 21 January, the Focata is lit, a great bonfire fed with juniper cut in the surrounding land: a deeply felt tradition that draws many emigrants of Acquaviva back from other regions and from abroad.