Carotid surgery in patients with carotid stenosis and contralateral occlusion is generally followed by a higher operative morbidity and mortality-rate than patients with monolateral stenosis. To verify our experience, the records of 167 patients affected with internal carotid stenosis with contralateral occlusion operated on between 1978-1991 were reviewed. They were 139 males and 28 females with a mean age of 62.3 years, and represent the 16% of the patients operated on for carotid lesion in the same time period. The indications for surgery were TIA or RIND in 52 patients, minor stroke or stroke in 9, non hemispheric symptoms in 19; 22 patients were asymptomatic, and 75 presented symptoms unrelated to the operated stenosis. The operative morbidity and mortality-rate of the whole sample were: stroke-rate 4.8%, mortality-rate 3% and cumulative stroke + mortality-rate 5.4%. In particular the operative risk was higher in patients operated on for stroke or for vertebro-basilar symptoms, while patients with reversible symptoms and asymptomatic patients had a significant lower stroke-rate both in the post-operative period and in the follow-up (p < 0.02). Patients operated on for completely asymptomatic lesions and for contralateral borderline symptoms had no operative symptoms. Relationships between operative complications and pre or per-operative monitoring have been analyzed; our results suggest a more extensive use of intraluminal shunt and an operation under general anaesthesia in patients with ischemic areas shown by a pre-operative SPECT or with a cerebral infarct even if SPECT monitoring does not suggest its use.