Most sea anemones are harmless to human beings. However, a few species are highly toxic. It could induce hemolysis and renal injuries in resembling hemolytic uremic syndrome (HUS). Only a few cases are reported. We described a HUS after sea anemone sting in this case. A 37 year-old male patient with no underlying disease visited our hospital with right thigh pain and rash, swelling in November 2019. He was shot in an sea anemone during the skuba diving in Cebu, Philippines on the day before one day. He complained mild headache, fever and was diagnosed with thrombocytopenia and renal failure. We suspected sepsis due to cellulitis and administered broad spectrum antibiotics. However, thrombocytopenia and renal dysfunction gradually worsened and schistocytes were identified on the peripheral blood smear test. We performed ADAMTS 13 and other autoimmune antibody tests, and plasma exchange in advance. Autoantibody tests and ADAMTS 13 were confirmed to be in the normal range and culture test result were negative. We continued conservative treatments such as hemodialysis and blood transfusion. Genetic test associated with atypical HUS was not abnormal and we diagnosed with typical HUS due to sea anemone toxin. Antibiotics and hemodialysis treatment continued, platelet count and serum creatinine was improved. Hemodialysis has stopped and his general condition has been steadily being observed. Hemolytic uremic syndrome due to sea anemone toxin is rare. Clinicians should be able to consider HUS in these situations and make quick decisions about treatment.