Acute bacterial meningitis (ABM) is a highly lethal disease. Available data support the use of corticosteroids in high-income countries, but the effect on mortality is still controversial. The effects of corticosteroids on mortality and sequelae were evaluated in the national Swedish quality registry. In total, during 1995-2014 1746 adults with ABM were included, of whom 989 were treated with corticosteroids (betamethasone, n = 766; dexamethasone, n = 248; methylprednisolone, n = 2), 498 were not given corticosteroids and in 259 patients data for corticosteroids were missing. Fatal outcome was observed in 8.9% of the patients in the corticosteroid-treated group vs. 17.9% in the non-corticosteroid-treated group (p