The purpose of this study is to describe the etiology, characteristics and outcomes of central nervous system (CNS) infections in patients with systemic lupus erythematosus (SLE), while also identifying prognostic and risk factors. Thirty-eight SLE patients with CNS infections were identified from review of all charts of patients with SLE hospitalized from January 1995 to June 2005. These patients were divided into 3 groups, i.e., Mycobacterium tuberculosis (TB), non-TB bacterial and fungal infection groups. Of the 38 SLE cases with CNS infections, TB was identified in 19 patients, Listeria monocytogenes in 3 patients, Klebsiella pneumoniae in 1 patient, Staphylococcus aureus in 1 patient, Gram's stain positive bacteria in 1 patient, Cryptococcus neoformans in 12 patients, and Aspergillus fumigatus in 1 patient. The rate of unfavorable outcome in patients with fungal infection was lower than in patients with TB (P=0.028) and non-TB bacterial CNS infections (P=0.046). SLE patients with TB or fungal CNS infections had a more insidious or atypical clinical presentation. Compared to SLE patients without CNS infections, those with CNS infections were more likely to have low serum albumin levels (P=0.048) and have been receiving higher doses of prednisolone at the onset of CNS infection (P=0.015) or higher mean doses of prednisolone within the previous year (P=0.039). In conclusion, low levels of serum albumin and higher doses of received prednisolone are important risk factors for the development of CNS infections in SLE patients.