We report a 13-year-old Indian boy with nephrotic syndrome caused by renal AA amyloidosis. Workup of the AA amyloidosis revealed chronic hepatitis B. Laser microdissection of the Congo-red-positive glomeruli and vessels followed by liquid chromatography and tandem mass spectrometry confirmed the presence of serum amyloid A (SAA) protein and ruled out hereditary and familial amyloidosis. Furthermore, mass spectrometry also detected a variant of SAA protein (SAA W71R).