INDEX: 1. The problem: the resilience of the res judicata to the CJEU’s attacks that undermine its stabilizing function. – 2. The “dialogue” between the Italian Supreme Court (Corte di Cassazione) and the Court of Justice of the European Union. – 3. The Olimpiclub Case and the defeat of the res judicata in the trial before the tax courts. – 4. The CJEU’s “attack” on res judicata concerning unfair terms in consumer contracts. – 5. Conclusions.