Having relevant indicator(s) of students’ school adjustment is the basis for making educational decisions with regard to an enormous scope of topics that refer to either individual students, a specific class, or even the entire school level. Thus, a major cornerstone in the effort to promote students’ school adjustment is the ability to correctly and accurately measure it. The problem of defining a given student’s state is a multi-aspect and multi-level challenge that is shaped by the local authorities’ guidelines, cultural norms, economic circumstances, and the student’s intellectual qualifications and personal characteristics. The existing literature suggests a rich list of measurements of the student’s feelings and the teacher’s evaluation of the student’s academic achievements, but parental and peer reflections are relatively underrepresented. This chapter advocates the priority of students’ subjective evaluations. Such measurements appear under various titles: students’ belonging, engagement, attitude, feelings, satisfaction, well-being, liking, burnout, sentiment, and more. In order to conduct routine evaluations of students’ school adjustment there is a need for a short and easily administered scale. For this end, the School Adjustment Questionnaire (SAQ) is presented as a possible example.