PurposeThis study aimed to define independent factors associated with the onset of early seizure (ES) amongst patients with cerebral venous thrombosis (CVT). MethodsThis retrospective cohort study recruited patients diagnosed with CVT and hospitalised between 2002 and 2020. Demographic, clinical, and seizure characteristics; neuroimaging findings; and clinical outcomes were compared between the seizure and non-seizure groups. Factors with p-values of <0.05 in univariate analysis were included in multivariate logistic regression analysis to determine independent predictors of ES. ResultsAmongst 180 CVT patients, the incidence of ES was 38.3%. Most seizures presented as the initial symptom. Focal to bilateral tonic-clonic seizure was the most common seizure type (82.6%). Recurrent serial seizure and non-fatal status epilepticus accounted for 56.5% and 8.7% cases, respectively. Intracerebral haemorrhage (adjusted odds ratio [aOR]=6.57, 95% confidence interval [CI], 2.25‒19.21, p = 0.001) and dependency status at admission (aOR=3.32, 95% CI, 1.08‒10.18, p = 0.036) independently predicted ES, whereas isolated increased intracranial pressure (aOR=0.05, 95% CI, 0.01‒0.24, p < 0.001), isolated headache (aOR=0.10, 95% CI, 0.02‒0.45, p = 0.002), straight sinus thrombosis (aOR=0.03, 95% CI, 0.00‒0.37, p = 0.007), and cavernous sinus thrombosis (aOR=0.50, 95% CI, 0.01‒0.53, p = 0.012) showed protective effects. ConclusionIntracerebral haemorrhage and dependency status at admission independently predicted seizures, whereas isolated increased intracranial pressure, isolated headache, straight sinus thrombosis, and cavernous sinus thrombosis showed preventive effects.