Vitritis is a relatively common clinical finding, and a significant number of patients present with vitritis as the major or only finding. The records of 199 patients coded "vitritis" at the Bascom Palmer Eye Institute were reviewed. Forty-seven patients fit in the category of "idiopathic vitritis" and formed a relatively distinct group of predominantly elderly woman who complained of floaters or blurred vision. The visual acuities were usually good and the anterior segments were generally normal. They had diffuse bilateral vitreous inflammation and either a normal fundus or reactive changes such as cystoid macular edema or preretinal "cellophane" membranes. Extensive medical evaluations were usually unremarkable. This study helps identify a group of patients with a typical presentation and rather characteristic eye findings. Additional work will be necessary to establish the pathogenesis, the natural course, and the efficacy of treatment.