A case of skin injuries due to stings by crown-of-thorns starfish, Acanthaster planci, in a 53-year-old Okinawan woman is reported. She went to a beach to gather shellfish on 8 April 2001 and fell to the ground with her left palm on a crown-of-thorns starfish that happened to be close to her. She hurried to the emergency section of our hospital. An emergency doctor sterilized the wound and administered an antibiotic, an analgesic agent and an injection of a tetanus antitoxin. He tried to remove the remaining spines from the palm with great difficulty. Because swelling and subcutaneous indurations of the left palm had persisted thereafter, oral and topical administration of corticosteroid started on 13 April. Physical examination at the dermatology section revealed approximately 10 stab wounds of the left palm with pus, subcutaneous bleeding and many abrasions around them. X-rays of the left hand showed foreign bodies, 2-10 mm in size, located on the lesions. The patient was treated with a topical injection of 2 mg triamcinolone acetonide (Kenacort-A), diluted fivefold with 1% Xylocaine, once a week. Some of the foreign body granulomatous lesions improved but pain and subcutaneous indurations persisted in most of the lesions. Because the X-ray photographs showed many remaining spines, surgical excision to remove them was performed under local anesthesia 3 months after the injury. All the symptoms improved after the operation. Scanning electron microscopic examination of the spines revealed that their tips had fragile lattice-like structures.