In recent years, the education data collected by international agencies has revealed a phenomenon that concerns education in the extracurricular context: private lessons, also terned shadow education. It was defined as private education outside school hours, which supports children and young people in their studies. It has been included among the most profitable industries in many countries, especially in Asia where the phenomenon had the greatest expansion. Thus, it represents a new market related to education, emerging in the world economy. Shadow education has been closely examined in South Korea and in the Asian countries, while there is scarce literature regarding Italy and other European countries. Given the relevance of this sort of education, it is important to understand its occurrence at the social level, and whether it may be different across geographical areas. The goal of this paper consists of outlining the situation of the shadow education in two different countries taking into consideration the different historical and cultural context. The focus is set on two prototypical countries, in both Europe and Asia: Italy and South Korea. Based on the 2015 PISA (Programme for International Student Assessment) document, data on the content of private lessons in mathematics in the two countries were analyzed through a series of chisquared comparisons. In cases where the content taught during the private lesson is the same as in school, it could be hypothesized that private lessons are given as reinforcement, repetition and recovery of what is done at school. Conversely, when the content is different, private lessons could be conceived as an improvement of what is done during school hours. Among the main results, it is highlighted that most of the private lessons in both countries focus on content regularly taught at school. Regarding additional contents, it emerged that in South Korea these are much more common than Italy. The two countries differ therefore in the type of contents that are conveyed and therefore in their function. Findings will be discussed to outline communalities and differences between the two contexts taken into consideration. In particular, the results mirror the cultural differences to the approach of shadow education and suggest implications for the management of both scholastic and extra scholastic activities.