The article deals with the problem of learning losses. The study is theoretical. The authors used the methods of comparative analysis and theoretical generalisation of modern approaches in educational science and practice to the causes of and conditions for overcoming learning losses, studying and interpreting the results of surveys of students and teachers of general secondary education institutions in Ukraine. The authors emphasised that in times of war, learning losses, together with psychological losses, losses at the level of infrastructure, teaching staff, etc. form a set of losses that are considered as losses of the educational system. It is stated that in Ukraine there is a process of developing procedures for studying the war times learning losses, as well as mechanisms for minimising them. The article describes the achievements of researchers of the Institute of Pedagogy of the National Academy of Educational Sciences of Ukraine on overcoming learning losses in primary school and at the level of general secondary education.Based on the research results the authors substantiate key principles that should determine the mechanisms/programmes for minimising and catching up with students’ learning losses: childcentredness: programmes for catching up with learning losses should meet the age and personal needs of students; safe educational environment, which should be physically and emotionally safe and child-friendly; integration of academic subjects to ensure the implementation of state standards aimed at developing key competencies; support for teachers in terms of security, psychological assistance, and professional development, taking into account martial law; consideration of regional and local specifics: the location of an educational institution in the frontline zone, in the occupied territory, in a relatively safe region, and the financial situation of the community. The authors conclude that the experience gained by international organisations and foreign countries in the context of the COVID-19 pandemic is valuable for Ukraine. At the same time, the factors that cause the suspension of the educational process and the work of schools in wartime are of a completely different nature. Given the complexity of learning losses in wartime, it is important to think about a holistic national strategy that would offer multiple and flexible mechanisms for their compensating and overcoming.