Vascular malformations are one of the most common lesions of the oral cavity. The lesion may be a congenital malformation observed in neonates or arteriovenous malformation observed in adults. Various surgical and medical managements are possible for vascular lesions which include surgical excision, laser therapy, cryotherapy, selective embolization, intralesional sclerosing agents, βâblockers and steroid therapy. Here we report a case of oral vascular lesion where intralesional injection with 30 mg/ml of sodium tetradecyl sulfate (STS) was given, which resulted in local complications with severe inflammatory response including pain, swelling, and surface ulceration that remained for 2 weeks. Sclerotherapy with STS still remain an effective agent in treating benign oral vascular lesions and provides alternative or support for surgical methods. Sometimes it can lead to undesirable complications like allergic reactions, local inflammatory response, etc.