Posterior Reversible Encephalopathy Syndrome(PRES) mainly develops in patients under immunosuppressive therapy after transplantation, or patients who suffer hemato-oncologic diseases, eclampsia, acute hypertensive encephalopathy related with nephrotic disease. Sudden headache, nausea, mental derangement, convulsion, vision problems are the main symptoms shown in PRES. It typically shows edema of occipito-parietal area of cortex or subcortex in Magnetic Resonance Imaging(MRI). A 10-year-old male was hospitalized with the chief complaint of headache, vomiting and dizziness for 3 days. He was treated for upper respiratory infection for 1 week before the hospitalization. Initial blood pressure was 145/95 mmHg, which was high for his age. Uninalysis showed microscopic hematuria(3+). The hypertension persisted even after the hospitalization, and re-checked blood pressure was 175/115 mmHg. The patient complained of headache, and after that, he suffered from alteration of mental status with dysarthria and generalized type of seizure events. The MRI showed lesions suggestive of PRES. He recovered to alertmental status after the blood pressure was controlled. Antistreptolysin-O(ASO) titer was increased and complement 3(C3) titer was decreased. The follow up MRI taken 1 month after the event became normal. We report a case of PRES related with contemporary hypertensive event in Acute Post-Streptococcal Glomerulonephritis(APSGN).