This study reports on serum interleukin 2-receptor (IL-2R) levels in uveitis patients.IL-2R is the mediator protein of interleukin 2 (IL-2), a mitogenetic cytokine of primarily immune cell interaction. Stimulated T-cells readily express IL-2R on their cell surface and release a soluble form into serum.The measurement of IL-2R serum levels was performed using a monoclonal antibody based ELISA with age and sex matched healthy blood donors serving as the control group.The increase of IL-2R serum levels in patients affected by heterochromic cyclitis Fuchs (HCF) and a small group of children with chronic anterior uveitis affected by juvenile rheumatoid arthritis (JRA) was statistically highly significant, when compared to the control group (n=84,α=0.01). Serum levels of patients with intermediate uveitis (IU), patients with HLA-B27 positive acute anterior uveitis (AAU) and patients with HLA-B27 negative AAU did not differ significantly from the controls.