This paper describes the development and validation of an instrument to assess how students deal with emotionally challenging classroom situations (the DECCS Questionnaire). The questionnaire is based on a vignette with one learning and one performance situation in a classroom, and is intended for students in grades 4 to 7. On a sample of N = 639 students (M[subscript age] = 10.6 years; SD = 1.25, 52.4% girls) in northwest Germany, factor analytic procedures for the subdimensions of students dealing with emotionally challenging classroom situations show that two factors can be distinguished each for students' appraisals, for students' adaptive behavior, for students' maladaptive behavior, and for students' desired teacher behavior. The questionnaire and subscales demonstrate good reliability and validity values. Thus, the DECCS questionnaire shows good psychometric properties and is well suited for determining how students deal with emotionally challenging classroom situations.