Some students experience unexpected, systemically unanticipated changes in their educational environment, such as changing schools or class, or perhaps repeating a year. Such educational pathways are labelled as ‘discontinuous’. They are recognised as disruptions in the educational settings and considered to be risk factors which may impinge on school achievement, behaviour, or overall well-being of a child. In this paper, we discuss the scale of the problem among eighth-graders from Ostrołęka, its probable causes, with particular emphasis on a family situation, and consequences, taking into account the maths and Polish language end-of-year test results in the seventh grade. The study has shown that changes disrupting the educational path carry a risk of greater school difficulties, especially in the case of maths (lower achievement, even when family characteristics relevant to the analysed relationship are controlled for). Therefore, it is important to take care – as much as it is possible – of the continuity of students’ educational environment, e.g. by reducing changes to those that are absolutely necessary (e.g. it should be carefully considered whether the changes in class composition between the third and fourth grade are necessary).