Purpose: The purpose of this paper is to describe a theoretically based coding framework for an integrated analysis and assessment of critical thinking in online discussion. Design/methodology/approach: The critical thinking assessment framework (TAF) is developed through review of theory and previous research, verified by comparing results to previous research, and checked for reliability by comparing results for multiple coders. Findings: Although process, structure, and quality of online discussions are assessed independently, a standard framework integrating these aspects for comprehensive assessment of critical thinking in online discussions is not found in literature review. The critical TAF described here offers a reliable and valid tool for integrating process, structure, and quality to assess critical thinking in online discussions. Research/limitations/implications: The critical TAF serves as a methodological tool for assessing critical thinking in online discussion. Further research should further assess the validity and reliability of this tool and should integrate the framework with assessments for other aspects of discussion such as social or instructor presence. Practical implications: The implementation of the critical TAF in future studies will ultimately help identify online educational activities and tools which best support development and application of critical thinking skills. Furthermore, it might be used to assess critical thinking of individual participants or small groups in a discussion. Originality/value: The critical TAF described in this paper provides a valid and reliable tool for integrated assessment of the process, structure, and quality of critical thinking in online discussions. (Contains 2 tables.)