We report a case of successful percutaneous treatment of a chronic post-traumatic splenic pseudocyst using alcohol as the sclerosing agent. A 26-year-old man presented with a symptomatic cystic mass located in the spleen. Aspiration of 300 ml of fluid was only temporarily effective, and therefore a drainage catheter was placed 3 days later. After histopathologic and microbiologic exclusion of a malignant or infectious origin, local sclerotherapy with alcohol was performed because of recurrence after percutaneous drainage. This therapy was repeated six times within 2 weeks. Two weeks later, the remaining volume was determined to be 16 ml. Six months after treatment the cyst was no longer visible. To our knowledge this is the first case of a chronic post-traumatic splenic cyst treated with alcohol. Percutaneous sclerotherapy of a symptomatic post-traumatic splenic pseudocyst may be an alternative to surgical treatment.