Abstract Background Despite the recent advances in the management of inflammatory arthritis, a considerable proportion of arthritis patients remain symptomatic. This cohort has recently been identified as ‘difficult to treat’ (D2T). In view of the limited evidence base, management of these patients has been a challenge particularly in view of its associated significant economic health burden. A better understanding of the D2T may help recognise or develop new therapeutic targets and facilitate earlier intervention in the disease course to prevent the progression of such condition. The aim of this work is to address the unmet needs in the management of D2T arthritis and develop a comprehensive approach towards the identification and proper assessment of those patients. Results At the completion of round 3 Delphi process, a total of 20 items were obtained and divided into 5 domains. From 88.9 to 100% of respondents agreed with the recommendations (ranks 7–9). All 20 of the clinical standards that the scientific committee identified were agreed upon in terms of wording, recommendation grade, and level of evidence (i.e. 75% of respondents strongly agreed or agreed). Conclusion D2T inflammatory arthritis remains a relevant clinical challenge, despite the endorsement of the treat-to-target approach and the availability of a broad range of targeted arthritis medications. This study provided a comprehensive definition of the condition to facilitate the identification of this patients’ group. It also highlighted the goals and principles aiming at providing an effective framework for D2T assessment, closely monitor and set up a strategy to intervene in standard clinical practice.