The port-wine stain, a relatively rare subgroup of capillary hemangiomas, usually involves the face and in children it may be associated with glaucoma. A series of 50 patients with facial port-wine stains had ocular examination at The Hospital for Sick Children, Toronto. When the facial areas supplied by both the ophthalmic and maxillary divisions of the sensory branch of the trigeminal nerve were involved (26 patients) there was about a 45% chance of diagnosing glaucoma, either as "true" glaucoma (with visual loss and raised intraocular pressure) or as "glaucoma suspect" (without visual loss). Involvement of the area supplied by either division alone was not associated with glaucoma.