Introduction. Primary acquired iris stromal cyst is rare in adults. In this group, they are generally stable lesions which require no treatment. Case outline. We describe a rare case of a small primary iris cyst in a 39-year-old patient, associated with unusual signs of irritation. Ultrasound biomicroscopy demonstrated iris stromal cyst measuring 3 ? 2 mm. A neodymium-doped yttrium aluminium garnet (Nd:YAG) laser cystotomy was engaged as the least invasive treatment approach. However, the cyst recurred soon after repeated laser treatment and sector iridectomy with excision of the cyst was performed. Five years after surgery there was no evidence of recurrence. Conclusion. Although more benign clinical course of primary stromal iris cyst is generally assumed in adults as compared to children, complete cyst removal seems to be mandatory for preventing cyst recurrence regardless of the cyst size or patient age. To the authors? knowledge this is the first documented report of Nd:YAG laser photodisruption of acquired primary iris stromal cyst in an adult.