COVID-19 primarily presents with respiratory involvement. Extrapulmonary manifestations as the sole manifestation also occur although rare. The kidney, being one of the organs with the greatest number of ACE receptors, is usually reported as part of multiorgan involvement. We report an early adolescent boy who presented with nephrotic–nephritic syndrome with severe kidney dysfunction from COVID-19 infection. He had low C3 and undetected antineutrophil cytoplasmic antibodies, antinuclear antibody and antistreptolysin O. Kidney biopsy revealed findings consistent with diffuse proliferative glomerulonephritis with a focal glomerular crescent formation and thin basement nephropathy. Due to the rapidly progressive deterioration of kidney function, he was given pulse methylprednisolone therapy followed by oral prednisone. Complete recovery was documented 12 weeks after the onset of post-infectious glomerulonephritis. The possible pathogenesis of glomerulonephritis in a patient with COVID-19, its differential diagnosis and treatment are discussed.