Little is known of the natural history and rate of sinus recanalisation after cerebral venous thrombosis (CVT). Although acute anticoagulation is effective, the duration of therapy remains speculative. We aimed to determine the relationship between sinus recanalisation and clinical outcome. We studied 12 consecutive patients with aseptic CVT with evidence of sinus thrombosis on initial magnetic resonance imaging, followed up 5-68 months after onset, using 15 repeat magnetic resonance scans in 9 of the patients to assess recanalisation. All patients initially had one or more thrombosed sinuses and were treated with anticoagulants for at least 6 months, including 3 with haemorrhagic infarction. Residual neurological deficits were present in only one patient. No patient had a recurrent thrombosis. Recanalisations was incomplete in 6 of the 9 cases. Sinus recanalisation after cerebral venous thrombosis does not correlate with clinical outcome. Although empirical, the general recommendation of 6 months anticoagulant therapy is appropriate.