Vascular malformations or even hemangiomas need therapeutic intervention if they start to cause clinical symptoms or personal discomfort. Different therapeutic modalities, including cryotherapy, corticosteroids, laser therapy, sclerotherapy, surgery, and/or embolization, can be performed successfully. Sclerotherapy with monoethanolamine is a relatively simple and effective method to treat low flow vascular lesions. We presented a report of six cases of vascular malformations treated with monoethanolamine. There were 3 male and 3 female patients, with an age range of 20 to 68 years. The patients were submitted to applications according to clinical response and/or tolerability. In all cases, low-flow vascular lesions were recorded and submitted to infiltration with 2.5% monoethanolamine, directly into the lesions. The volume applied was approximately the middle of affected area. Vascular lesions were characterized as low-flow due to absence of arterial pulsation and flat consistence. The sclerosis with 2.5% monoethanolamine resulted in complete or partial involution, without severe complications.