We divided 61 patients (111 eyes) with pars planitis into three groups based on clinical appearance. Patients in Group I had bilateral vitreous cells and bilateral pars plana exudates (36 patients, 72 eyes); patients in Group II had bilateral vitreous cells but a pars plana exudate in one eye only (14 patients, 28 eyes); and patients in Group III had vitreous cells and exudate formation in the single eye involved (11 patients, 11 eyes). The presence of a pars plana exudate was associated with more severe vitreous disease and increased incidence of cystoid macular edema.