Postoperative fibrin pupillary-block glaucoma, an uncommon complication of intraocular surgery, develops when an inflammatory fibrin membrane occludes the pupil, resulting in peripheral angle closure. We present a series of 4 patients with this condition and describe the role of anterior segment optical coherence tomography and ultrasound biomicroscopy in distinguishing fibrin pupillary-block glaucoma from other forms of postoperative acute glaucoma. Specific to this condition is the presence of a fibrin membrane across the pupil and accumulation of aqueous in the posterior chamber, as would be expected in pupil block, but with a clear separation between the intraocular lens and the iris. The possible risk factors are discussed and various treatment modalities reviewed.