Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder that causes congenital glaucoma. Previous experiences have shown that drainage procedures are often required to control associated glaucoma. The conventional surgical approach in trabeculectomy carries a significant risk of intraoperative expulsive hemorrhage. Here, we describe a modified approach of the conventional trabeculectomy technique, which may lower the risk of expulsive hemorrhage. A viscoelastic device was employed to maintain a steady intraocular pressure throughout the procedure. Details of the surgical technique and material used are described. One patient with congenital glaucoma associated with SWS underwent a successful trabeculectomy using the modified technique. Postoperative intraocular pressure was successfully reduced and no intraoperative complications occurred. We describe a successful case of trabeculectomy in a SWS case where a modified technique was applied.