Goodpasture’s syndrome is thought to be caused byan immunological disorder in which antibodies are directed against the glomerular and alveolar capillary basement membranes. The recognition of this process has been simplified by the technique of immunofluorescent staining; a linear staining pattern against IgG and C3 is found in Goodpasture’s syndrome. A case is presented in which two specimens of renal tissue taken at different stages of the illness, were examined by this technique. Immunofluorescent findings were negative in the first of these specimens, but were positive in the second specimen. Such findings cast doubt on any simple immunological explanation of the disease.