Four cases of the simultaneous occurrence of bilateral diffuse melanocytic uveal tumors were studied by us. In each case, the patient had an associated systemic malignant neoplasm diagnosed by biopsy or at autopsy. There was no evidence of metastatic melanoma in any patient. Clinically, the patients experienced rapid loss of vision, and cataracts were usually present. Multiple pigmented and nonpigmented placoid iridic and choroidal nodules, as well as serous retinal detachment, frequently were noted. Histopathologically, the uveal tracts of both eyes were diffusely infiltrated by preponderantly benign-appearing nevoid or spindle-shaped cells. Areas of necrosis within the tumors and scleral involvement were commonly seen. We believe this constellation of findings constitutes a new syndrome in which there is a bilateral, diffuse proliferation of melanocytic cells throughout the uvea in association with a systemic malignant neoplasm.