The patron of Costermano sul Garda is Saint Anthony the Abbot, celebrated on 17 January in the Church of Sant'Antonio Abate.
The town's various hamlets keep their own traditions alive: in Marciaga, on the last weekend of July, the Festa dell'Ospite is held, a popular feast with local specialities and folklore, while on 8 December the Festa dei biscotti is celebrated, with tastings of the local chestnuts known as «biscotti». The town also holds the Hermitage of Santi Fermo e Rustico.
