The great majority of patients identified as having a 'minimal change lesion' accompanying the nephrotic syndrome have a primary or 'idiopathic' disorder. Nevertheless, it is quite apparent that a similar or identical lesion can appear consequent to a growing number of underlying diseases; it is then known as 'secondary minimal change disease'. The predisposing conditions include neoplastic diseases, toxic or allergic reactions to drugs, infections, auto-immune disorders and other miscellaneous entities. These disorders are reviewed and catalogued in this contribution.