Lymphangioma is a congenital malformation of the lymphatic system, commonly seen in the neck. Operation was the treatment of choice but it is difficult to resect the lymphangiomas completely. The aim of this study is to evaluate the result of intralesional injection of OK-432 as a treatment strategy of lymphangioma in children. Medical records of 51 cases of lymphangioma from March 1996 to February 2001 were reviewed retrospectively. Intralesional injection of 0.1mg OK-432 in 10ml normal saline was performed after the aspiration of as much fluid as possible. The location of the lesion was the face and neck in 26 patients, the chest wall in 14, the extremities in 9, and the abdominal wall in 2. The cystic type was present in 45 patients and the cavernous type in 6. Four postoperative recurrent cases were included. Fluid aspiration from the lesion was impossible in 5 patients. Development of fever after injection was observed in 27 patients and local inflammatory reaction was in 5 patients. There was no scar formation at injection sites. Complete shrinkage was observed in 20 patients, remarkable shrinkage in 23, slight shrinkage in 3, and no response in 5. Cystic type or aspiration-possible cases showed better outcome than cavernous type or aspiration-impossible cases. All of four recurrent cases after surgical excision showed at least remarkable shrinkage. These results indicate that intralesional injection of OK-432 is a safe and satisfactory treatment modality of lymphangiomas in children and might be considered as a treatment of choice, even in recurrent cases.