There is increasing evidence that cytokines play an important role in the pathogenesis of uveitis. The aim of this study was to determine the presence of cytokines in the aqueous humor (AH) of patients with chronic idiopathic uveitis (CU). Patients with uveitis (n=10) were compared to those undergoing cataract surgery (n=1) for non-inflammatory eye diseases. ELISA's for the detection of cytokines (IL-1, IL-2, IL-6, TNF-α) in aqueous humor were developed that allowed the measurement of multiple cytokines present in low concentrations. Interleukin-6 was found to be elevated in the aqueous humor of two patients (20%) with CU, but in none of the controls. Interleukin-1-α, Interleukin-2 and TNF-α were not detected in the AH of patients or controls. TGF-ß was detected in the aqueous of all patients and controls, using a bioassay.