Kimura disease (KD) is an autoimmune eosinophilic granulomatous disorder with generalized lymphadenopathy. A handful of pediatric patients with renal disease have been described, none of whom have been African-American (AA). We present an AA boy with KD and nephrotic syndrome (NS). Two months after stopping steroids, fever, asthma, eczema, and proteinuria recurred. His NS did not relapse but his platelet count decreased to 51,000/microl (x10(6)/l). On restarting prednisone, his platelet count normalized. A kidney biopsy revealed 23 of 37 glomeruli obsolescent and advanced damage with over 50% of cortical tissue replaced by interstitial fibrosis and chronic inflammation. Glomerular immunofluorescence was largely negative; very intense linear anti-tubular basement membrane (TBM) deposits of IgA, IgG, C3, and C4 were noted. At present, 36 months from onset, serum creatinine is 1.2 mg/dl (106 micromol/l). We present a 4-year-old AA boy with KD, NS, relapsing thrombocytopenia, and renal damage with anti-TBM antibody.