OBJECTIVES: Rheumatoid arthritis (RA) can result in disability, lower quality of life, and higher societal costs.  Pain is one of the primary symptoms of RA, yet few studies have sought to understand how the pain experience varies day-to-day.  The aim of this study was to use a mobile survey in a real-world environment to better understand the pain experience of those with RA. METHODS: Patients with RA were invited to participate in a 7-day pain diary study (with an option of continuing for up to 14 days).  Patients downloaded a study app, which included a statement of informed consent along with a baseline survey (to assess demographics and basic health history).  The McGill Pain Questionnaire (MPQ) was administered each day, based on a reminder sent through the app, along with the opportunity to provide qualitative data through pictures, video, and free text.  RESULTS: N=40 respondents participated (87.50% female, mean age = 33.63). The most common comorbidities were insomnia (82.50%), anxiety (72.50%), and depression (62.50%). Only 20% rated their pain intensity was “mild”; the remaining 80% rated their pain as more intense. The “hot/burning” and “exhausting” pain dimensions (as assessed from the MPQ) were the most consistent over the diary (within-person SD=0.10 for each) whereas “punishing” (within-person SD=0.45), “shooting” (SD=0.27), and “gnawing” (SD=0.28) were the most variable.  Further, pain described as “punishing” was most strongly associated with greater pain intensity (r=0.43, p<.05). CONCLUSIONS: Using a mobile survey, this study was able to collect the real-world pain experience of patients with RA. The results suggest that some dimensions of pain are stable (e.g., “burning” pain) whereas others are more variable (e.g., “punishing”) and different dimensions have different relationships with pain intensity.  Real-world mobile diary studies can inform the ebbs and flows of the pain experience to better understand health outcomes.