An elderly pseudophakic man with advanced open-angle glaucoma underwent Nd:YAG laser posterior capsulotomy. Pigment deposits were also removed from the anterior lens surface with laser applications. In spite of pre- and post-laser treatment with topical apraclonidine (Iopidine) and normal IOP 1 hour postoperatively, the patient presented the next day with visual acuity of 20/300, corneal edema, pain, and IOP of 60 mm Hg. Prompt treatment reduced the pressure and normal visual acuity was achieved. While apraclonidine prevents early post-laser elevation of IOP in most cases, some pressure elevations may be delayed or persist longer than the duration of action of the drug. Examination of patients with advanced glaucomatous optic nerve damage is recommended the day after anterior segment laser surgery, even when apraclonidine is used at the time of laser surgery and IOP is normal 1 to 2 hours postoperatively.