W e aimed to report a case of bilateral acute iris transillumination and pigment dispersion related to oral moxifl oxacin that used a higher dosethan recommended. A 43-year-old woman who presented with redness, pain, blurred vision, and high intraocular pressure (IOP) 10 hoursafter taking six oral moxifl oxacin tablets because of pneumonia was referred to our clinic for differential diagnosis. Slit-lamp examinationrevealed conjunctival hyperemia, endothelial dusting, fl oating anterior chamber pigments, and diffuse transillumination for both irises. IOPwas in the normal range with both topical and systemic antiglaucomatous treatment. The patient experienced several fl are-ups within threemonths, especially in the fi rst month. The pigment cells decreased in both the anterior chamber and trabecular meshwork, however, diffusetransillumination is still continuing in both eyes. Although the relationship between oral fl uoroquinolones and uveitis is still controversial, thepresented case with severe signs and symptoms shortly after taking high dose oral moxifl oxacin supports this relation.