To assess the safety and efficacy of percutaneous sclerotherapy of slow-flow vulvar vascular malformations. An IRB-approved retrospective review was undertaken of all patients who underwent percutaneous sclerotherapy of slow-flow vulvar vascular malformations between January 2008 and August 2017. Patient demographics, lesion characteristics, procedural factors, and clinical outcomes were identified through a review of the electronic medical record and relevant imaging. Seven female patients (ages 7-32 years) with slow-flow vulvar vascular malformations underwent a total of 14 percutaneous sclerotherapy treatments using the 3% sodium tetradecyl sulfate foam technique. Two cases were associated with Klippel-Trénaunay syndrome and one with Servelle-Martorell syndrome. Presenting symptoms included generalized pain or discomfort (n = 6), dyspareunia (n = 1), voiding difficulties (n = 1), and cosmetic concerns (n = 1). All sclerotherapy procedures were technically successful. Clinical follow-up was available in six patients. Two patients reported near-complete resolution of symptoms after a single treatment. Three patients experienced initial relief but developed symptomatic recurrence after one year and required repeat treatment with subsequent resolution of symptoms. One patient experienced a gradual improvement in symptoms requiring a total of five treatments. One procedure (7.1%) resulted in minor labial cutaneous ulceration which resolved with conservative management. There were no major complications. Percutaneous sclerotherapy of slow-flow vulvar vascular malformations proved safe and effective in this limited cohort. While repeat therapy was necessary in the majority of cases, nearly all patients experienced durable symptomatic relief.