Acute lymphoblastic leukemia has several presentations associated with bone marrow and extramedullary involvement. The unusual presentation may be due to the infiltration of leukemic cells in any organ. An 11-year-old girl presented with fever and vomiting, since one day before admission after starfish biting during swimming. Her vital signs were: blood pressure 150/100 mmHg, pulse 98 beats per minute, respiration 18 breathes per minute, and temperature 37.2 °C (99 F). Laboratory work-up showed blood urea nitrogen 38 mg/dl and creatinine 2.8 mg/dl. In peripheral blood smear, few atypical cells, mild anemia (Hb: 9.2 g/dl), and mild thrombocytopenia (Platelet: 109,000/μL) were detected. Bone marrow aspiration and immunophenotyping were in favor of acute precursor B cell type lymphoblastic leukemia. The patient had a favorable response to treatment after initiating high-risk chemotherapy. Therefore, acute renal failure can be a rare initial presentation of acute lymphoblastic leukemia, and azotemia will improve with an early chemotherapy treatment.