We report a case of successful percutaneous treatment of a congenital splenic cyst using alcohol as the sclerosing agent. A 14-year-old female adolescent presented with a nonsymptomatic cystic mass located in the spleen that was believed to be congenital. After ultrasonography, a drainage catheter was placed in the cavity. About 250 ml of serous liquid was extracted and sent for microbiologic and pathologic studies to rule out an infectious or malignant origin. Immediately afterwards, complete drainage and local sclerotherapy with alcohol was performed. This therapy was repeated 8 days later, after having observed 60 ml of fluid in the drainage bag. One year after treatment the cyst has practically disappeared. We believe that treatment of splenic cyst with percutaneous puncture, ethanolization, and drainage is a valid option and it does not rule out surgery if the conservative treatment fails.