The aim of our research is to check if the combined use of radionuclide angiography and Doppler-sonography leads to correct screening of carotid lesions in the neck, independently from the indexes of reliability of the individual examinations. 125 cerebrovascular patients (for a total of 250 carotid studies) were investigated with radionuclide angiography and Doppler-sonography. 100 of these carotids were also angiographically investigated. On the basis combined angioscintigraphic and Doppler results, these patients have been classified in four groups. When both non-invasive examinations result negative, the angiography shows pathological arteries only in 22% of cases. When only radionuclide angiography is positive, the angiography shows pathological findings in 63% of cases: when only Doppler is positive, the angiography confirmation occurs in 72% of cases. Finally, when both non-invasive tests results positive, there is always arterial pathology in the angiography.