We reviewed the medical records of 60 consecutive patients (28 men and 32 women; aged from 13 to 63 years) with the diagnosis of dissection of the internal carotid artery (ICA), and with available clinical and neurosonological follow-up. Ten cases occurred after trauma and 50 cases were spontaneous. Angiographic evidence of fibromuscular dysplasia of the ICA was found in 23% of the cases. Unilateral headaches or neck pain associated with focal cerebral ischemic symptoms or oculosympathetic palsy were the most common findings. Less frequent symptoms such as isolated cranial nerve palsies and pulsating bruits were also observed. Follow-up ranged from 3 to 144 months (mean, 37.5 months). A favourable outcome occurred in 73.7% of the cases with a follow-up of 6 months or more, and seemed to depend on the severity of the ischemic cerebral deficit associated with the ICA dissection. 68% (41/60 cases) of our patients developed stroke and 18% (11/60 cases) experienced a transient ischemic attack, which occurred as the initial manifestation of the ICA dissection in 28.8% (15/52 cases) of the cases, and with a delay (more than 24 hours) in the other cases. Evidence of embolization in the cerebral arteries was found in 36% of the cases with stroke (15/41 cases). Anticoagulant therapy, given in 34 of our patients, seems to be justified by the fact that a considerable risk exists for cerebral emboli in association with ICA dissections; no serious neurological complications were observed in our series as a result of this anticoagulant therapy. Doppler sonography follow-up diagnosed a recanalization in 67.8% of the stenotic or occlusive dissections, most of them being completed within the first 6 months (92%). Recurrence of ICA dissection is exceptional but occurred in one of our 60 cases, 2.5 years after the first event.