© Copyright 2015 The Journal of Rheumatology. All rights reserved. Objective. To develop a plan for harmonizing outcomes for people undergoing total joint replacement (TJR), to achieve consensus regarding TJR outcome research. Methods. The TJR working group met during the 2014 Outcome Measures in Rheumatology (OMERACT) 12 meeting in Budapest, Hungary. Multiple conference calls preceded the face-to-face meeting. Brief presentations were made during a 1.5-h meeting, which included an overview of published systematic reviews of TJR trials and the results of a recent systematic review of TJR clinical trial outcome domains and measures. This was followed by discussion of potential core set areas/domains for TJR clinical trials (as per OMERACT Filter 2.0) as well as the challenges associated with the measurement of these domains. Results. Working group participants discussed which TJR clinical trial outcome domains/areas map to the inner versus outer core for core domain set. Several challenges were identified with TJR outcomes including how to best measure function after TJR, elucidating the source of the pre- and post-TJR joint pain being measured, joint-specific versus generic quality of life instruments and the importance of patient satisfaction and revision surgery as outcomes. A preliminary core domain set for TJR clinical trials was proposed and included pain, function, patient satisfaction, revision, adverse events, and death. This core domain set will be further vetted with a broader audience. Conclusion. An international effort with active collaboration with the orthopedic community to standardize key outcome domains and measures is under way with the TJR working group. This effort will be further developed with new collaborations.