Patient-generated data are a cornerstone of individualized multiple sclerosis (MS) treatment. MyMS, an interface for patient-reported outcomes (PROs) was developed by the Finnish MS Register to enable systematic collection of PROs. MyMS collects data on demographics, lifestyle factors, disease-related factors, and validated questionnaires, including the Quality of Life Questionnaire (15D), the Multiple Sclerosis Impact Scale (MSIS-29), and the Fatigue Severity Scale (FSS). At the end of 2020, the patient-reported Expanded Disability Status Scale (PREDSS), the EuroQOL-5 Dimension (EQ-5D), the Fatigue Scale for Motor and Cognitive Functions (FSMC), and the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) were added. As of January 1, 2023, 1201 individuals with MS (79% female) have added data to MyMS. Of the validated PRO measures (PROMs), the 15D, MSIS-29, and FSS are the most used. The mean PREDSS score is 3.0 and median disease duration is 6.4 years. According to the existing PROMs, patients report mildly compromised quality of life and problems with fatigue and cognition. The patient interface of the Finnish MS Register consists of data from 17 of 21 counties with well-being services. The interface is used by 10% of Finnish individuals with MS. The addition of the PREDSS, EQ-5D, FSMC, and MSNQ to the interface has increased health care professional and patient interest in the use of PROMs. We suggest that PROs should be integrated into electronic health records to improve shared decision-making and diminish documentation burden.