Churg-Strauss syndrome (CSS) is a rare systemic vasculitis associated with asthma and eosinophilia. Withdrawal of corticosteroids in asthmatic patients is known to be a powerful trigger for the development of CSS. Renal involvement in patients with CSS is commonly manifested as antineutrophil cytoplasm antibody-associated necrotizing crescentic glomerulonephritis, however, concomitant CSS and the nephrotic syndrome or IgA nephropathy are rare. We report a 12-year-old boy with CSS associated with IgA nephropathy that developed while tapering oral steroids. The patient had a history of the nephrotic syndrome and asthma.