Background Transient flares of RA are of great concern for patients, but are not considered in clinical trials, and data on the frequency, duration, and severity of those flares are scarce. Objectives To perform a survey assessing features of RA transient flares, as well as physicians' and patients' attitudes to those flares. Methods 1245 RA patients from the AFPric French RA association were asked to fill a standardized questionnaire on internet about their experience of flares during the last year. No definition for RA flare was given, since all the 99 French (other) patients previously interviewed during the building of the “Flare instrument” spontaneously understood RA flares as transient worsening of RA, and not as definitive loss of efficacy of ongoing treatments (1). Nearly all items from the “FLARE” instrument were present in the survey questionnaire, except C-reactive protein, which was replaced by the occurrence of flu-like illness (fever, chills) just before or during flares. Results 403 RA patients responded (89% women, 52.5±9 years-old, disease duration 12±5 years). RA was treated by DMARDs (67%), and/or biologics (50%), and/or prednisone (36%). 83% of responders thought they were able to distinguish transient RA flares from other conditions (including osteoarthritis). Only 17% of patients acknowledged that flares could be related to transient oversight of their RA treatments. 95% reported at least one transient flare during the last year, and 50% at least one per month. The duration of those flares was shorter than a week in 68%, but mean flare intensity was 7.02±1.98 on a 0 (no flare) to 10 (extremely severe flare) scale. Most patients (90%) were convinced that these transient flares could induce lasting damage, but only 15% tried to anticipate rheumatology visit. 80% reported their flares during visits, but patients felt that rheumatologists modified their treatment just to prevent further flares in 1/3 cases only (32%). Frequency, duration and intensity of flares did not seem to differ according to treatments (DMARDs (67%) and/or biologics (50%) and/or prednisone (36%)), or their combination. Most patients (89%) would accept to fill a questionnaire designed to retrospectively detect and quantify recent RA flares just before a visit. They also agreed with the items selected for building the “Flare instrument” to retrospectively assess them. The only exception was the need to increase of prednisone dose, approved by only 43% of responders. One item of the “Flare instrument” (result of C-reactive protein) has been replaced by an item not included in this tool (the onset of fever or chills during flares): 35% patients responded that they did experience such flu-like symptoms during a flare within the last year. Conclusions Transient RA flares should be more considered, as only 15% of patients tried to anticipate rheumatology visit. Those transient flares might be driven by immunological process different from those controlled by current treatments, since they seem as frequent and severe whatever the combination of treatments.