Background: Effective management of clinical assessment tools is critical in stroke and brain injury rehabilitation research. Managing rehabilitation outcome measures (ROMs) scores and training therapists in multicenter randomized clinical trials (RCTs) is challenging. Objects: The aim of this study was to develop a web-based platform, the Korean Rehabilitation Outcome Measurement (KoROM), to address these limitations and improve both therapist training and patient involvement in the rehabilitation process. Methods: The development of the KoROM spanned from June 2021 to July 2022, and included literature and web-based searches to identify relevant ROMs and design a user-friendly platform. Feedback from six physical therapy and informatics experts during pilot testing refined the platform. Results: Several clinical assessment tools categorized under the International Classification of Functioning, Disability, and Health (ICF) model are categorized in the KoROM. The therapist version includes patient management, assessment tool information, and data downloads, while the patient version provides a simplified interface for viewing scores and printing summaries. The master version provides full access to user information and clinical assessment scores. Therapists enter clinical assessment scores into the KoROM and learn ROMs through instructional videos and self-checklists as part of the therapist standardization process. Conclusion: The KoROM is a specialized online platform that improves the management of ROMs, facilitates therapist education, and promotes patient involvement in the rehabilitation process. The KoROM can be used not only in multi-site RCTs, but also in community rehabilitation exercise centers.