An adult female was found to have a variation of the left basal vein of Rosenthal after presenting with complaints of headache. The vein, in this case, drained directly into the confluence of sinuses instead of the great vein of Galen. Variation of the basal vein is likely due to the embryonic development of the deep cerebral venous system as primitive structures either differentiate further or regress with age. Such changes may result in the uncommon presentation seen in this case. To our knowledge, this is the first case reported of the basal vein draining into the confluence of sinuses.