Many recent studies have stressed the importance of students' self-regulated learning (SRL) skills for successful learning. Although primary teacher educators are aware of the importance of SRL for their students, they often find it difficult to implement SRL opportunities in their teaching. To support teacher professional development, an SRL model was described in a previous theoretical study. In the present article, this SRL model is elaborated towards the "Self-Regulated Learning Opportunities Questionnaire" (SRLOQ) that can be applied by primary teacher educators as a diagnostic instrument for classroom settings. A four-phase research design is applied, consisting of scale development, score validation, further validation of the SRLOQ in primary teacher education and a confirmatory factor analysis. Finally, a single case study is described that illustrates the usefulness of the SRLOQ in classroom practice.