IN 1927 Alport1 described a hereditary syndrome of chronic progressive nephropathy and hematuria associated with sensorineural hearing loss. To date, very little information has been available on the temporal bone histopathology of this condition. We have been fortunate enough to obtain four sets of temporal bones (eight ears) from cases with probable Alport's syndrome. The findings are presented in this paper. In the patient with Alport's syndrome, the renal disease is manifested in early life as asymptomatic hematuria, often intermittant, and later accompanied by albuminuria or cylinduria. Eventual renal failure and uremia may be aggravated by superimposed infection. Males are usually affected earlier and more severely, seldom living beyond age 30, with hematuria often the only finding in females. Early renal biopsies may be normal, later showing nonspecific findings of acute or chronic glomerulonephritis or pyelonephritis or both. Interstitial foam cells have been emphasized as diagnostic but are neither