Four patients with primary intraocular reticulum-cell sarcoma were presented. All of the patients were followed at the Wilmer Institute for periods of up to ten years. All had decreased visual acuity and a uveitis that was refractory to standard forms of therapy. In one case, the correct diagnosis was made clinically. At autopsy, two of the patients had systemic reticulum-cell sarcoma, a third had intracranial reticulum-cell sarcoma, and in a fourth case the disease process was confined to the eye. The literature is reviewed and the clinico-pathologic features of the total of 14 cases are analyzed. It is emphasized that a recalcitrant uveitis was present in almost all of the cases reported. Differential diagnosis and methods of diagnosis are discussed.