Posterior reversible encephalopathy syndrome is a clinical radiographic syndrome of heterogeneous etiologies. Developing hypertensive encephalopathy following post-streptococcal glomerulonephritis is a known but uncommon manifestation and developing posterior reversible encephalopathy syndrome in such a situation is very rare. We report a case with contrast-enhanced computed tomography and magnetic resonance imaging findings of posterior reversible encephalopathy syndrome in the background of acute post-streptococcal glomerulonephritis. A thirteen-year-old Sri Lankan boy presented with a focal fit by way of secondary generalization with duration of 10 minutes, and developed 2 similar fits subsequently following admission. He later developed severe hypertension with evidence of glomerulonephritis, which was diagnosed as acute post-streptococcal glomerulonephritis. A contrast-enhanced computed tomography imaging of brain done on day-3 revealed non-enhancing low-attenuating areas in fronto-parietal regions. A T2 weighted film of magnetic resonance imaging was done on day-10 of the admission and found to have linier sub-cortical hyper intensities in both parietal regions which were compatible with the radiological diagnosis of posterior reversible encephalopathy syndrome. Post-streptococcal glomerulonephritis is an important cause of acute nephritic syndrome especially in children. This case report illustrates a rare association of posterior reversible encephalopathy syndrome in a patient with post-streptococcal glomerulonephritis.