•Standardization of health outcomes can improve the quality of healthcare.•The present RRMS standard set of variables can help to optimize its management.•The study provided an opportunity to pool different stakeholders' perspectives. Standardizing health outcomes is challenging in clinical management, but it also holds the potential for creating a healthcare system that is both more effective and efficient. The aim of the present study is to define a standardized set of health outcomes for managing Relapsing-Remitting Multiple Sclerosis (RRMS). The project was led and coordinated by a multidisciplinary scientific committee (SC), which included a literature review, a patient-focused group, three nominal group meetings, and two SC meetings. 36 outcome variables were included in the standard set: 24 clinical (including weight, smoking habit, comorbidities, disability, mobility, diagnosis of secondary progressive multiple sclerosis, relapsed-related variables, radiological variables, cognitive status and disease-related symptoms), nine treatment-related (pharmacological and non-pharmacological information), and 3 related to the impact of RRMS on the patient's life (quality of life, pregnancy desire, work-related difficulties). In addition, experts also agreed to collect 10 case-mix variables that may affect but cannot be controlled as part of the management of the condition: 4 sociodemographic (age, sex, race, and employment status) and 6 clinical (height, date of diagnosis and first episode, serological status, early symptoms, and number of relapses pre-diagnosis). The information provided through the present standard set of outcome variables can improve the management of RRMS and promote patient-centred quality care. Display omitted