Objective - To define the relationships between levels of chemokine receptor (CCR)5+ T-cells in blood and cerebrospinal fluid (CSF) of optic neuritis (ON) and control patients (CON). Materials and methods - Expression of CCR5 and related receptors CCR1 and CCR3 on CD4- and CD8-positive T-cells in peripheral blood mononuclear cells (PBMC) and CSF was determined by flow cytometry in 20 patients with ON, 16 control patients with lumbar spondylosis, 20 healthy controls (HC) and 16 patients with rheumatoid arthritis (RA). Results - CCR5+CD4+ and CD8+ T-cells were enriched in CSF, compared with PBMC, in both ON and CON patients (all P < 0.001), and the percentages of CD4+/CCR5+ (r = 0.917) and CD8+/CCR5+ (r = 0.828) cells in PBMC and CSF were strongly and directly correlated. CCR5+ T-cells produce high amounts of tumor necrosis factor-α (TNF-α) and very low amounts of interleukin-5 (IL-5). Closely related receptors (CCR1, CCR3) were not altered. Conclusion - Our data suggest an involvement of CCR5 in T-cell accumulation in the inflamed central nervous system.