Acute kidney injury (AKI) is characterized by an abrupt decrease in glomerular filtration rate, manifesting as an increase in serum creatinine or oliguria. Nephritic syndrome, a manifestation of glomerulonephritis, presents with hematuria, hypertension, decreased urine output, and edema. This case report discusses an 11-year-old Asian boy who presented with decreased urination, shortness of breath, hypertension, and bilateral leg edema. Urinalysis revealed hematuria, proteinuria, and dysmorphic erythrocytes, while serum creatinine was elevated with a decreased estimated glomerular filtration rate (eGFR). The patient had a positive ASTO test, indicating poststreptococcal glomerulonephritis as the underlying cause of nephritic syndrome and AKI. Although most cases of poststreptococcal glomerulonephritis in children have a favorable outcome, some cases can develop into a serious, life-threatening condition that requires careful attention. This case highlights the importance of early detection and management of poststreptococcal glomerulonephritis to prevent progression to nephritic syndrome and AKI, especially in resource-limited settings. Modest examination modalities can facilitate early detection and faster patient management, particularly in developing countries, to reduce the risk of mortality associated with severe AKI in pediatric patients.