In a 2 1/2 years period between 1.1.1984 and 30.6.1986 292 carotid endarterectomies were carried out on 235 patients. The aim of this study was to find out prognostic factors influencing early results and long term patency. Therefore we worked on 33 parameters for statistical significance. A high statistical correlation was found in three working hypotheses: 1. Higher incidence of neurological troubles when coincidence with stenosis in the rear brain arteries. 2. Shorter life expectancy if previous insults occurred. 3. Higher rate of restenosis when preoperatively high grade stenosis. A lower statistical correlation was found in the following hypotheses: 1. Older patients have more concomitant risk factors for arteriosclerosis than younger. 2. Older patients present preoperatively a more severe degree of arteriosclerosis. 3. Risk of severe insult is correlating with age. For the rest of the 33 parameters no statistical significance was found. The results are presented in detail.