The blood-brain barrier (BBB) is a critical extrameningeal site of injury during bacterial meningitis, manifested by enhanced BBB permeability (BBBP). Previous methods to measure altered BBBP during meningitis involve radioactive materials, or are poorly quantified. Europium (EU) is a fluorescent, non-radioactive metal that is a sensitive and stable marker. Europium fluorescence can be measured with a spectrophotometer capable of time-resolved fluorescence (TRF). We used EU-albumin (EU-A) to examine BBBP in experimental lipopolysaccharide (LPS) induced meningitis. The results presented here introduce a simple and accurate method for measuring BBB permeability.