A 61-year-old woman with NVG was referred to our department with left ocular pain and blurred vision for a duration of 5 days. She had been treated for diabetes mellitus 4 years ago with hypoglycemic agents and for asthma 10 years ago with bronchodilators. At the first visit, the best-corrected visual acuity and IOP were 20/40 and 13 mm Hg in the right eye and 20/60 and 37 mm Hg in the left eye, respectively. The right eye showed no inflammation in the anterior segment and posterior segment. The left eye showed ciliary hyperemia, infiltrating cells, hyphemia, rubeosis iridis, and cataract in the anterior segment (Fig. 1a, b); however, vitreous opacity or retinal vasculitis was not observed in the posterior segment (Fig. 1c). Gonioscopy examination detected nodules and rubeosis on the trabecular meshwork in the left eye. Fluorescence angiography did not detect any retinal vasculitis or retinal ischemia caused by diabetes mellitus (Fig. 1d). Serum examination detected slight increases in blood glucose (201 mg/dL), HbA1c (6.8%), and erythrocyte sedimentation rate (17 mm/h). C-reactive protein, angiotensin-converting enzyme, and interleukin-2 receptor were within normal ranges. Bilateral hilar-mediastinal lymphadenopathy was not detected on chest X-ray. Serum herpes simplex virus (HSV) IgM, HSV IgG, cytomegalovirus (CMV) IgM, CMV IgG, and CMV antigen were negative, and a multiple broad-range polymerase chain reaction (PCR) test using anterior humor did not detect human herpes virus (HHV) 1-8, 16S rRNA, 28S rRNA, tuberculosis, or toxoplasmosis. We diagnosed the left eye as NVG caused by unknown anterior granulomatous uveitis, and topical corticosteroid (0.1% betamethasone 6 times/day) and anti-glaucoma agents (0.005% latanoprost 1 time/day, 0.1% brimonidine 2 times/day, 0.4% ripasudil hydrate 2 times/day, and 0.5% dorzolamide 3 times/day) were initiated. beta stimulant was not used because of asthma. On the next day, IOP was still high (28 mm Hg), and additional oral acetazolamide 500 mg/day was initiated. After 1 week of treatment, inflammation and rubeosis iridis had diminished (Fig. 1e), and IOP had decreased to 20 mm Hg. After 1 month, inflammation and rubeosis iridis had completely resolved, and IOP had decreased to 13 mm Hg (Fig. 1f). Gonioscopy also detected the regression of hyphema and rubeosis. Treatments were then tapered, and there was no recurrence for 1 year.