Congenital nephrotic syndrome is a severe disorder caused by increased permeability of the glomerular capillary leading to massive proteinuria. Typically, this disorder presents in the first three months and is caused by inherited mutations in genes encoding structural proteins of the podocyte slit membrane and, as such, is usually irreversible. Medical management is often insufficient to stem the enormous losses of protein, and the patients require nephrectomies. Here, we present results for a patient with congenital nephrotic syndrome of unknown etiology which responded to treatment with an angiotensin-converting enzyme inhibitor alone. The patient's proteinuria relapsed when the medication was stopped, but went into complete remission after restarting treatment. This remarkable response is discussed in the light of recent investigations into the effect of angiotensin II on podocyte integrity.