OBJECTIVE: The Contextual Factors Working Group aims to provide guidance on addressing contextual factors in rheumatology trials within OMERACT. METHODS: During the Special Interest Group session at OMERACT 2018, preliminary results were presented from a case scenario survey and semistructured interviews, including contextual factors mentioned in these. A group-based exercise sought to identify and rank important generic contextual factors. RESULTS: A total of 79 candidate factors were listed. Across the 3 groups, gender/sex, comorbidities, and the healthcare system were ranked as most important. CONCLUSION: The identified important contextual factor domains may be considered a provisional list pending further research.