Headache was only sign of CVT in 17 patients. The lateral sinus was the most frequently involved sinus (n = 15). Onset of headache was progressive in 11, acute in 3, and thunderclap in 3 patients. Once established, the headache was continuous in 15, diffuse in four and unilateral in 13, usually ipsilateral to the occluded lateral sinus. No specific risk factor or cause was found. All had a favourable evolution.