PURPOSE: To determine the frequency of retinal thickening (RT) in eyes with iridocyclitis and to examine the correlations among anterior chamber (AC) inflammation, RT, and visual acuity. DESIGN: Retrospective, observational case series. METHODS: Records were reviewed of patients seen at the Duke University Eye Center Uveitis Clinic from January 2002 through March 2008. Patients with unilateral iridocyclitis without panuveitis, vitreitis, pars planitis, posterior uveitis, or a combination thereof who had undergone optical coherence tomography (OCT) of both eyes were included. The AC cell grade and OCT-RT measurements were recorded. Subretinal fluid and intraretinal cysts were determined from OCT scans according to Duke Reading Center guidelines. RESULTS: Forty-three patients were studied. RT typically was present in a ring-like distribution around the fovea. The median difference between the study eye and fellow eye in RT was statistically significant for total macular volume (TMV) and for all OCT subfields (P < .001). In the study eye, there was a modest correlation between the RT and AC cell grade for the OCT-TMV (P = .039; r(2) = 0.1) and the subfield comprised of the quadrants in the outer ring on OCT (P = .027; r(2) = 0.12), and between RT and visual acuity for OCT-TMV and all but the central subfields (P = .003 to .007; r(2) = 0.261 to 0.227). RT decreased after anti-inflammatory therapy. CONCLUSIONS: RT is strongly associated with iridocyclitis and decreases after treatment. RT, as determined by OCT, is a useful clinical parameter to evaluate patients with iridocyclitis and to monitor response to treatment.