Analyzing the achievements of Polish doctrine, the role of interpretation of the law seems to be underestimated, which is particularly evident in the laconic explanation by its representatives of the so-called “misinterpretation” as a basis for a cassation complaint. Meanwhile, the adoption by the legislator of the “incorrect interpretation” as the basis for lodging a cassation appeal proves the importance of the role of interpretation in the eyes of the legislator. The aim of the appeal in cassation is to ensure a uniform interpretation of the law, in which legal certainty is sought. However, according to a method and interpretation of the law which is commonly used abroad in Germany, for example, legal security is ensured not so much by the 201 uniformity of jurisprudence, but by the constitutionality of the judiciary’s decisions based on constitutional values which ensure the fairness of decisions.