Between 1965 and 1979, 934 patients underwent 1,057 operations for extracranial carotid stenosis at this institute, and over a recent 30-month period 463 patients underwent 511 operations of this type. This number is equal to the total of operations performed during the years 1965-1976. The increase in the frequency of carotid artery surgery has been more marked in patients of over 70 years. The percentage of elderly patients has increased from 17.5% to 27% in the recent period. In the latter group of 511 operations, results were good in 93.17% of cases, while there was a mortality rate of 1.95% (1% of which were directly related to the surgery), in 1.95% the neurologic condition deteriorated and in 3.13% there was no change. In the first period the mortality rate for patients over 70 years of age was 7.69%. In the second it was 3.27% (1.63% of which were due to non-neurologic causes), 4.09% deteriorated, in 2.18% there was no change and good results were obtained in 90.46%.