The authors present two cases of lymphangioma of the cervicofacial region, treated with a new investigational drug in North America, OK-432 (picibanil), a sclerosing agent intralesionally injected. Both patients had been treated surgically and had recurrence of the tumor. Intralesional injection of OK-432 without aspiration was employed for the first patient, and after aspiration in the second patient. A change in consistency of the tumor, manifested by softening, was followed by marked shrinkage. No complication either locally or systemically has occurred during the follow-up period (10 to 16 months). In both cases, satisfactory results were obtained, resulting in definite reduction in size and improvement in cosmetic appearance. The authors recommend OK-432 intralesional injection for surgically challenging lymphangioma. Their results support those of a recent Japanese study using OK-432 as sclerosing therapy for unresectable lymphangioma.