This retrospective observational study aims to report the clinical characteristics and surgical results in eyes with Posner-Schlossman syndrome (PSS), and compare these outcomes between cytomegalovirus (CMV)-positive and -negative eyes.We reviewed the medical records of 21 consecutive immunocompetent patients clinically diagnosed with PSS between the years 2010 and 2018. Aqueous humor was collected from all the affected eyes to detect if CMV was present, and polymerase chain reaction (PCR) was performed using the herpesvirus family primers.The average period between the initial PSS attack and aqueous humor sampling at our institute was 9.3 years. Out of the 21 patients, 62% were CMV-positive. Regardless of CMV status, the mean intraocular pressure (IOP), mean deviation (MD), and central corneal endothelium cell (CEC) density, at the initial examination at our institute were already significantly worse in the affected eyes than in the unaffected eyes (all P values < .05). The average visual acuity (VA) was only significantly worse in the CMV-positive group (P = .02). Out of all the patients, those that were CMV-positive had undergone more glaucoma surgeries (P = .056). Fourteen patients underwent either a trabeculectomy (TRAB) or a trabeculotomy (LOT), and their IOP significantly reduced following surgery (P < .001). In 85.7% of those that had surgery, their IOP was successfully lowered to less than 20 mm Hg.Long-lasting PSS causes a decrease in VA, MD, and the CEC density. A prompt diagnosis is required, and an appropriate treatment plan should be formulated. In those patients with PSS that develop uncontrolled glaucoma, both TRAB and LOT may be effective in controlling IOP.