The Dutch Constitution prohibits the courts from reviewing the constitutionality of Acts of Parliament. They are however obliged to assess whether statutory regulations are compatible with international treaties. The ban on constitutional review is laid down in the Constitution.
This does not mean that this type of legislation is at no point reviewed in the light of the Constitution. This is in fact done during the preparatory stage by the bodies involved in enacting legislation (the Council of State in its advisory role, and the legislature, in other words, the government and both Houses of Parliament). It is first and foremost the responsibility of these bodies to ensure that no legislation is passed that is in conflict with the Constitution.