This paper aims to present how mental testing has been introduced in Hungary. Interest of local experts in child psychology was fed by both the international development of psychology and practical problems of education. Adaptation of Binet-Simon test was carried out with the contribution of the most prominent representatives of Hungarian psychology and pedagogy. Although the introduction of mental testing had its practical benefits in education, debates about the nature of intelligence did not reach a standstill. Hungarian psychologists claimed that quantitative assessment of intelligence does not reflect the complexity and individuality of human mind.