OBJECTIVES: To describe hospital admissions for managing multiple sclerosis (MS) relapses in the Brazilian Public Healthcare System (BPHS). METHODS: Data from the 2009-2012 period were collected from the BPHS Hospital Information System (SIH/SUS), which aggregates administrative data from inpatient admissions in public hospitals in the entire country. Individual claims coded as “MS Relapse Inpatient Treatment” in the SIH/SUS (regardless ICD-10 codes) were identified in the database and compiled by state and year. RESULTS: We obtained data on 5,922 individual MS relapse-related claims, homegenously distributed among the 4 years. They represented an overall cost of BRL3,729,921 for the 2009-2012 period (ranging from BRL806,722 in 2010 to BRL1,033,649 in 2012). The 4-year national average cost per inpatient admission BRL629, with mean LOS of 7.51 days and ICU days of 0.22. The in-hospital mortality rate ranged from 0.65%-1.60%. The 2012 national rate of MS relapse-related hospitalization in the general population (per 100,000, absolute number of admissions / total population) was 0.79, varying from 0.03/100,000 in Alagoas (Northeast region) to 1.78/100,000 in Santa Catarina (South region). All parameters were consistently different among Brazilian states. In-hospital deaths were very rare in this sample not allowing robust conclusions. It was possible to identify significant outliers in the mean cost per admission when states were separately considered (2012 data: from BRL323 [n=3] in Sergipe to BRL 4,596 in Espírito Santo [n=4]). São Paulo was the state with higher absolute number of hospitalizations in all years. In 2012, the state had 526 admissions, mean cost per event of BRL810, 4 in-hospital deaths (0.76%), mean LOS=6.16, and mean ICU days of 0.36. CONCLUSIONS: BPHS administrative hospital database can provide insightful information about MS relapse-related admissions. Both geographical and time trends can be examined using SIH/SUS secondary data, particularly for diseases with highly specific procedure codes.