Patient: 38 years of age, female, BCVA 1.0/1.0, IOP 15/16 mmHg. Ocular Medical History: detection of an iris lesion initially on routine biomicroscopy as a focal shallowing of the anterior chamber and an elevation of the peripheral iris. General Medical History: empty. General Complaint: none. Purpose: to present ultrasonic biomicroscopy finding of an iris lesion initially detected on routine biomicroscopy. Methods: Colour Photography Anterior Segment, Ultrasonic biomicroscopy. Findings: Colour Photography Anterior Segment: elevated area at 11 o’clock with a focal shallowing of the anterior chamber, no ectropion uvea or pupillary distortion was noted. Ultrasonic biomicroscopy: thin walled cyst with low internal reflectivity near the iridociliary junction. Discussion: The assessment of an iris lesion should minimally include visual acuities, biomicroscopy and gonioscopy. Most iris cysts are initially detected on routine biomicroscopy as a focal shallowing of the anterior chamber and an elevation of the peripheral iris. Shields JA et al (1) concluded that the great majority of them are ophthalmic curiosities which require no treatment. The great majority of primary iris cysts, particularly those which arise from the iris pigment epithelial layers, are stationary lesions which rarely progress or cause visual complications. The major clinical importance of primary iris cysts lies in their similarity to neoplasms of the iris and ciliary body. Attention should be given to the internal reflectivity, with notation of any associated feeder vessels and pigment dusting, all of which may potentially indicate malignancy. Literature: (1) Shields JA, Kline MW, Augsburger JJ. Primary iris cysts: a review of the literature and report of 62 cases. Br J Ophthalmol. 1984 Mar;68(3):152-66.