• PURPOSE: To evaluate the outcome of sodium morrhuate 5% injections in patients with low flow vascular lesions, which consist of orbital lymphangiomas, and in one patient with intraosseous cavernous hemangioma. • DESIGN: Prospective, interventional consecutive case series. • METHODS: Intralesional sodium morrhuate 5% was injected under direct visualization or under radiographic guidance to six patients with orbital lymphangiomas and one patient with intraosseous cavernous hemangioma. Comprehensive eye examination and follow-up imaging studies were performed. MAIN OUTCOME MEASURES: Lesion size was evaluated by orbital imaging and clinical examination, visual acuity, exophthalmos, and posttreatment complications. • RESULTS: Seven patients (four female, three male; average age, 33 years) were included. Six patients were diagnosed with orbital lymphangioma, and one patient was diagnosed with intraosseous cavernous hemangioma. Patients received an average of 2.6 ± 2 intralesional injections of sodium morrhuate, with a range of one to six injections and a mean volume of 0.9 ± 0.8 ml (range, 0.2 to 2.1 ml). Lesions showed a decrease in size an average of 50% (33%) and ranged from minimal (10%) to near total resolution (85%). Visual acuity and intraocular pressure remained unchanged; exophthalmos decreased an average of 1.5 ± 1.8 mm. Complications included one case of orbital hemorrhage that resolved spontaneously and transient keratopathy in all patients with anterior orbital lesions. • CONCLUSION: Intralesional sclerosing therapy with sodium morrhuate 5% is effective in tumor debulking in patients with orbital lymphangioma and is not associated with vision-threatening complications. It may be a better alternative to surgery for low flow orbital tumors, which includes lymphangioma.