BACKGROUND We developed a prognostic score to predict dependency and death after cerebral venous thrombosis (CVT) to identify patients for targeted therapy in future clinical trials.. METHODS We used data from the International CVT Consortium. We excluded patients with pre-existent functional dependency. We used logistic regression to predict poor outcome (modified Rankin Scale 3-6) at 6 months and Cox regression to predict 30-day and 1-year all-cause mortality. Potential predictors derived from previous studies were selected with backward stepwise selection. Coefficients were shrunken using Ridge regression to adjust for optimism in internal validation. RESULTS Of 1454 patients with CVT, the cumulative number of deaths was 44 (3%) and 70 (5%) for 30 days and 1 year, respectively. Of 1126 patients evaluated regarding functional outcome, 137 (12%) were dependent or dead at 6 months. From the retained predictors for both models, we derived the SI2 NCAL2 C score utilizing the following components: absence of female Sex-specific risk factor, Intracerebral hemorrhage, Infection of the central nervous system, Neurologic focal deficits, Coma, Age, lower Level of hemoglobin (g/L), higher Level of glucose (mmol/L) at admission, and Cancer. C-statistics were 0.80 (95%CI 0.75-0.84), 0.84 (95%CI 0.80-0.88) and 0.84 (95%CI 0.80-0.88) for the poor outcome, 30 days and 1 year mortality model, respectively. Calibration plots indicated good model fit between predicted and observed values. The SI2 NCAL2 C score calculator is freely available at www.cerebralvenousthrombosis.com. CONCLUSIONS The SI2 NCAL2 C score shows adequate performance for estimating individual risk of mortality and dependency after CVT but external validation of the score is warranted.