<p>The results of earlier studies indicate that school maladaptation is associated with a number of negative consequences, including poor academic performance, increased anxiety and unpopularity of the child among peers. However, reliable instruments for timely identification of school adaptation difficulties are not yet available in the Russian-speaking space; the use of foreign instruments is not possible due to cultural differences and peculiarities of the organisation of the educational process in different countries. This study highlights the development of a school adjustment questionnaire, including determining its optimal structure and assessing the feasibility of relying on self-reported information about school adjustment. Two identical versions of the questionnaire were developed, one for children and one for teachers. Sixteen teachers and 232 first-grade pupils participated in the study. Through a combination of exploratory and confirmatory factor analysis, a four-factor model of the teacher questionnaire was found to have the highest goodness of fit, including scales assessing cognitive activity, behaviour regulation, social inclusion and psycho-emotional stress. Data from children themselves did not prove to be reliable enough for differentiated assessment of aspects of school adaptation. The study has drawn the necessary conclusions for the further development of an instrument to assess school adaptation of children in Russia.</p>