OBJECTIVE To compare the clinical characteristics and visual prognosis of patients with anterior uveitis (AU) and intraocular fluid analysis positive for rubella virus (RV), herpes simplex virus (HSV), or varicella zoster virus (VZV). METHODS Retrospective, observational study. METHODS The study included 106 patients with AU and positive polymerase chain reaction (PCR) results, Goldmann-Witmer coefficients (GWCs), or both, for RV (n = 57), HSV (n = 39), or VZV (n = 10). METHODS Clinical records of the included patients were analyzed retrospectively; demographic constitution, ophthalmologic characteristics, and visual prognosis were compared. METHODS Age, gender, and diverse clinical and laboratory characteristics, including course and laterality of AU; prevalence of positive results for PCR, GWC, or both; conjunctival redness; corneal edema; history of keratitis; presence of keratic precipitates; synechiae; heterochromia; and grade of inflammation. In addition, complications and visual acuity at 1 and 3 years of follow-up were recorded. RESULTS All 3 types of viral AU were characterized by unilateral involvement (80%-97%). Rubella virus AU was characterized by younger age at onset and chronic course and typically was associated with cataract at presentation. Heterochromia was present in 23% of RV AU patients. Anterior uveitis associated with HSV or VZV occurred characteristically in older patients and frequently followed an acute course. Clinical features associated with herpetic AU included conjunctival redness, corneal edema, history of keratitis, and development of posterior synechiae. Herpes simplex virus AU often had severe anterior chamber inflammation, whereas the presence of vitritis was more common in RV AU and VZV AU. The prevalence of documented intraocular pressure (IOP) of more than 30 mmHg (25%-50%; P = 0.06) and development of glaucoma (18%-30%; P = 0.686) were similar in all 3 groups. Focal chorioretinal scars were seen in 22% of RV AU eyes, in 0% of HSV AU eyes, and in 11% of VZV AU eyes (P = 0.003). Visual prognosis was favorable for all 3 groups. CONCLUSIONS These observations identify clinical differences between RV AU, HSV AU, and VZV AU and may be of particular value to ophthalmologists who are unable to carry out intraocular fluid analysis to discriminate between these types of viral AU. BACKGROUND The author(s) have no proprietary or commercial interest in any materials discussed in this article.