Background. Ischemic stroke (IS) seriously impacts the quality of life of survivors. Chinese medicine (CM) has been developed for more than 2000 years and plays a key role in the treatment of ischemic stroke. Many Chinese medicine clinical trials have been conducted; however, the heterogeneity of outcome measurements and reporting limits implications of the findings in clinical practice and health policy development. Therefore, it is important to develop a core outcome set (COS) that should be used and reported in trials for ischemic stroke treated by Chinese medicine. This protocol describes the process of developing the IS-CM-COS. Methods and Analysis. The development of the COS will involve the following four steps: (1) A list of outcomes reported in the registered and published Chinese medicine trials of ischemic stroke will be extracted by conducting a systematic literature review. (2) An additional outcome list will be collected by semistructured interview to patients with ischemic stroke. (3) A two-round Delphi survey will be performed to prioritize and condense the outcomes. (4) In the consensus meeting, a final recommended COS will be developed. Discussion. The COS could improve the reliability and consistency of outcome reporting. We hope that this IS-CM-COS will be used in the future Chinese medicine trials for the treatment of ischemic stroke and improve research quality. Trial Registration. This study was registered with the Core Outcome Measures in Effectiveness Trials Initiative (http://www.comet-initiative.org/studies/details/1282). Copyright © 2020 Qianwen Xie et al.