The author examines the role of the judge-made law in civil law's system, with special regard to Italian legal system. In fact, the article 101 of the Italian Constitution states that judges are subject to the law. The analysis shows the legitimate room for judge-made law under Italian Constitution, despite a debatable doctrinal evolution. Then the contribution compares judge-made law with some recents degenerations in the Italian jurisprudence. The author puts them together under the formula "occasional case law". The occasional case law frustrates not only the principle of legal certainty, but also the true meaning of constitutionalism, that is the idea that every public authority's power can and should be legally limited.