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.