Surgery is considered the gold standard in the treatment of lymphoceles, however this is not feasible for all cases. We report the successful treatment of a supraclavicular lymphocele by intralesional application of the sclerosing agent OK-432. After a total of three intralesional injections of OK-432, the cyst had disappeared completely and the patient was free of symptoms. Thus, intralesional application of OK-432 is considered a highly effective treatment for cystic masses such as lymphoceles.