General legal position of an individual in terms of education is shaped by the norms of constitutional weight. Among them a special place is taken up by the principle of equal access to education, which is one of the guarantees of the right to education. In the author’s opinion, the above mentioned principle has a close relation to educational diagnostics, especially its normalized part, which is didactic measurement. Therefore, an extralegal element, which is the measurement (of its quality), has a significant influence on the legal position of an individual and determines the possibility to use one of the most fundamental rights. From the pedagogical perspective, the author proposes taking into account the legal environment in which educational diagnostics functions, and which – although roughly – he presents in the article, whereas from the legal perspective he points out to the necessity of taking into account the educational diagnostics’ conditioning in the evaluation process of implementing equal access to education.