Resumen: In the context of the COVID-19 pandemic, the co-circulation of influenza and SARS-CoV-2 viruses may have severe complications for vulnerable populations. For this reason, the World Health Organization pointed to the 2020–2021 anti-influenza campaign as being of special relevance. Our aim was to assess the 2020–2021 influenza vaccination coverage, and its associated factors, among patients in a Spanish multiple sclerosis (MS) unit. A cross–sectional study was conducted. People attending the MS unit of the Clinical Hospital of Zaragoza during 2020 were included. Variables were obtained by reviewing records. Associations with 2020–2021 influenza vaccination were analyzed using bivariate analysis and a multiple logistic regression model. A total of 302 patients were studied; 62.6% were women, whose mean age (standard deviation) was 47.3 (11.5) years. The 2020–2021 influenza vaccination coverage was 55.3% (59.8% in women and 47.8% in men). A total of 89.7% had at least one other indication for vaccination (e.g., immunosuppressive treatment in 225 patients). The variables associated with getting vaccinated were being female (adjusted odds ratio (95% confidence interval) (aOR (95%CI) = 2.12 (1.12–3.99)), having received the 2019–2020 influenza vaccine (aOR (95%CI) = 31.82 (14.71–68.86)) and being born in Spain (aOR (95%CI) = 12.91 (1.07–156.28)). Coverage is moderate compared to other countries. It is necessary to develop strategies to improve it, especially in men and those born outside Spain. Idioma: Inglés DOI: 10.3390/vaccines10101766 Año: 2022 Publicado en: Vaccines 10, 10 (2022), 1766[9 pp.] ISSN: 2076-393X Factor impacto JCR: 7.8 (2022) Categ. JCR: MEDICINE, RESEARCH & EXPERIMENTAL rank: 24 / 136 = 0.176 (2022) - Q1 - T1 Categ. JCR: IMMUNOLOGY rank: 32 / 161 = 0.199 (2022) - Q1 - T1 Factor impacto CITESCORE: 7.0 - Medicine (Q1) - Immunology and Microbiology (Q2) - Pharmacology, Toxicology and Pharmaceutics (Q1)