We assessed alterations of the blood-aqueous barrier in 43 eyes with malignant melanoma (31 choroidal and 12 ciliary body), 40 eyes with benign uveal tumors, and 199-age matched normal control eyes. Aqueous flare was quantified with the laser flare-cell meter and correlated with clinical and histopathologic findings. Aqueous flare (photon counts/ms) was significantly higher in melanoma eyes (20.91 +/- 12.40) than in eyes with benign tumors (4.26 +/- 1.55) (P < .0001) and normal control eyes (3.99 +/- 1.14) (P < .0001). In melanoma eyes, clinical and histologic findings associated with significantly increased aqueous flare values were as follows: tumor height, serous retinal detachment, tumor necrosis, lymphocytic tumor infiltration, and tumor hemorrhage. Development and growth of uveal melanomas are accompanied by marked alterations of the blood-aqueous barrier. The noninvasive laser flare-cell meter may give useful additional information about malignant and benign uveal tumors.