This article describes the prevalence of regular, somewhat irregular, very irregular and interrupted educational trajectories in Brazilian municipalities, by calculating the educational trajectories’ regularity indicator, drawing from the School Census Longitudinal Dataset. The results show that only about 52% of the teenagers that should have concluded the first nine years of basic education from 2015 to 2019 and 41% of those that should have completed high school between 2018 and 2019 had regular educational trajectories. These proportions are, on average, even lower for students with disabilities, males, Black and Indigenous populations, those in schools where the student body has low socioeconomic background and/or those living in municipalities from the North, Northeast and South of Brazil. It is noted that the educational trajectories’ regularity indicator captures student permanence dimensions not contemplated by the Basic Education Development Index (Ideb - Índice de Desenvolvimento da Educação Básica), such as student dropout, and that it could be used as a tool to guide municipal policies to promote basic education quality and equity.