OBJECTIVE: By surveying a multiple sclerosis (MS) population, we tested the hypothesis that influenza vaccine uptake would not meet public health targets and that vaccine misconceptions would contribute to lower than desired uptake. METHODS: In spring 2020, we surveyed participants in the North American Research Committee on Multiple Sclerosis Registry regarding vaccinations. Participants reported whether they had received hepatitis A, hepatitis B, pneumococcal, shingles, varicella, measles/mumps/rubella, tetanus, or influenza vaccines. Participants who had not received influenza vaccine last year reported the reasons. We summarized responses descriptively. Using multivariable logistic regression, we assessed participant characteristics associated with uptake of seasonal influenza vaccine. RESULTS: Of 5,244 eligible respondents, 80.8% were female, with a mean (SD) age of 61.8 (10.1) years. Overall, 43.0% (2,161/5,032) of participants reported that their neurologist had ever asked about their immunization history. The percentage of participants who received the seasonal flu vaccine last year ranged from 59.1% among those aged 18-24 years to 79.9% for persons aged ≥65 years. Among those who did not get the influenza vaccination, the most common reasons were personal preference (29.6%), concerns about possible adverse effects in general (29.3%), and concerns that the vaccine would worsen their MS (23.7%). CONCLUSION: Vaccination uptake is lower than desired in the MS population compared with existing recommendations, including for seasonal influenza. Misconceptions about the safety of vaccination in the context of MS and personal preference appear to play important roles in vaccination choices, highlighting the importance of education about these issues.