The school closure as an emergency measure in front of the COVID-19 pandemic has generated unprecedented challenges for the education systems worldwide. In the Spanish case, this closure has been developed in a profoundly unequal system, characterised, among other aspects, by school segregation indexes that are among the highest in Europe. The objective of the article is to analyse the impact of the lockdown on educational inequalities, focusing on the school expression of these inequalities. Specifically, it is aimed at exploring the diversity of strategies adopted by the different schools during the first period of the lockdown, analysing their effects in terms of learning opportunities for children and young people. The analysis is based on a questionnaire answered by 2 777 teachers in Catalonia from pre-school until upper secondary education, and it is structured in four main axes: 1) the educational priorities of the schools during the lockdown; 2) the channels of communication with their students; 3) the pedagogical activities carried out during this time; and 4) the difficulties that teachers consider their students face to follow the course remotely. The results of the analysis show the impact of COVID-19 on the worsening of educational inequalities, expressed by a high inequality of conditions between educational schools to articulate their teaching processes and guarantee the learning of all the students.