Utilizing chromatographic and radioimmunoassay techniques, we measured the concentration of leukotriene (LT) B4 and LTC4/D4/E4 in the aqueous humor of 14 patients with uveitis and seven patients undergoing penetrating keratoplasty or routine cataract extraction. Leukotriene B4 was detected in 11 of 14 patients with uveitis (mean, 0.96 pmole/mL), and LTC4/D4/E4 was found in 12 of 14 patients with uveitis (mean, 2.0 pmole/mL). In the control group, LTB4 was detected in six of seven patients (mean, 0.57 pmole/mL), and LTC4/D4/E4 was found in six of seven patients (mean, 1.9 pmole/mL). Leukotriene levels did not correlate with clinically assessed aqueous cell and flare. Mean levels of LT in patients with uveitis receiving corticosteroids were nearly double those found in non-steroid-treated patients. Despite apparent differences in LT levels, none of the above differences reached statistical significance.