Background: Laser therapy is the optimal approach for treating port-wine stains, but whether it is effective for patients with facial dermatomal port-wine stains and Sturge-Weber syndrome is undetermined. This project aimed to verify the incidence of Sturge-Weber syndrome and glaucoma within the population, compare the response in syndromic and nonsyndromic patients with facial dermatomal port-wine stains to laser, and determine the treatment response in relation to dermatome and color. Methods: The authors retrospectively reviewed 874 patients with facial portwine stains (203 displayed a dermatomal pattern). Pretreatment and post-treatment photographs were assessed clinically and recorded on a statistically reliable percentage gradient. Results: Sturge-Weber syndrome was diagnosed in 30 patients. Twelve patients had glaucoma, with the port-wine stains involving the ophthalmic (V-1) division of the trigeminal nerve. The highest proportion of patients with glaucoma came from those with involvement of the maxillary (V-2) and/or mandibular (V-3) division of the trigeminal nerve. No patients had Sturge-Weber syndrome with V-3, port-wine stains alone. After laser therapy, only 45 percent of syndromal patients and 55 percent of nonsyndromic patients had a satisfactory outcome (> 50 percent) in color and size reduction of dermatomal port-wine stains. Conclusions: The incidence of Sturge-Weber syndrome was 3 percent in patients with a facial port-wine stain. There was an increased risk of Sturge-Weber syndrome with involvement of V, port-wine stains and no risk with involvement of V-3 port-wine stains alone. Laser treatment produced unsatisfactory outcomes in patients with facial dermatomal port-wine stains. V3 port-wine stains responded best and V, worst to laser.