Currently, much research on cognitive diagnostic assessment (CDA) focuses on the development of statistical models estimating individual students’ attribute profiles. However, little is known about how to communicate model-generated statistical results to stakeholders, and how to translate formatively diagnostic information into teaching practices. This study proposed an integrative framework of diagnosis connecting CDA to feedback and remediation and, meanwhile, demonstrated empirically the application of the framework in an English as a Foreign Language (EFL) context. Particularly, the empirical study presented procedures of integrating diagnostic assessment to EFL reading curriculum through four phases of planning, framing, implementing, and reflecting. The results show that these procedures, influenced by the teacher’s orientation to diagnostic assessment and approach to EFL teaching, affected students’ perceptions of diagnostic assessment, their attitudes toward remedial instructions, as well as their learning outcomes on EFL reading. The results also provide evidence to the effectiveness of the integrative framework proposed in this study, showing that the framework could serve as practical guidance to the implementation and use of diagnostic assessment in the classroom.Overall, this study indicates that the diagnostic approach is a more effective way to provide instructionally useful information than other test and assessment approaches that do not differentiate strengths and weaknesses among students with the same total score.