Cerebral vein thrombosis (CVT) is a rare complication of spontaneous intracranial hypotension (SIH). When to suspect a thrombotic disorder during the course of intracranial hypotension is not fully elucidated. A 48-year-old woman was admitted because of SIH with no signs of CVT on neuroimaging. The occurrence of diplopia and blurred vision 12 days later led to the performance of further investigations, which revealed thrombosis of the left lateral sinus, in the absence of variations in the headache characteristics. Among the other 4 cases of SIH clearly preceding the occurrence of CVT reported so far, only one had a change in the headache pattern related to CVT development. Although a change in the characteristics of headache is considered a marker of CVT in patients with SIH, this is not invariably part of the clinical scenario. Any new neurologic finding on exam in the disease course should raise a suspicion of venous thrombosis, thus prompting further specific investigations.