There is no formal process of mandatory disclosure in Belgium. Parties are only required to produce documents on which they rely, which will be served on the opposing party and filed with the court. Consequently, the obligation to provide disclosure is a mere duty to produce the documents that support a party's case and upon which that party wishes to rely. Parties are bound to an obligation to cooperate in good faith with respect to the production of documents.

It should be noted, however, that in certain cases the court may order the parties, or even third parties, to make specific disclosure of certain documents, either on request of the parties or of its own motion provided that indications exist that such document constitutes evidence of a relevant fact. Belgian law does not allow unspecified disclosure requests or "fishing expeditions".