For the Romanian legal system, the case law does not have the quality of formal source of law. Nevertheless, the legal reality, also seen from a historical perspective, has demonstrated the essential role of the judicial practice in interpreting and enforcing the law, in constructing the argumentative practices, in clarifying the will of the legislator, and in discovering less obvious meanings of the legal norms, and last but not least to the unification of legal thinking and practice. Therefore the case law, together with the doctrine, is an important component of the Romanian legal system. Staring from these considerations, in this study we aim to emphasize a few aspects of constitutional case law. We are underlining its contribution to the emergence of the constitutionality control of laws in Romania. Under the influence of the Constitution of 1866, which did not regulate such a control in an institutional manner, the courts have assumed this competence by interpreting the law and by jurisprudential way. There are also presented and analyzed important contributions of the case law of the Constitutional Court, but also of the judiciary courts to the development of constitutionality control in our country. We support the idea that the case law currently plays an important role in the interpretation of the constitutional norms, including in terms of deepening the forms of constitutional control.