Isolated giant cerebral varix (IGV) is an uncommon vascular lesion that represents a diagnostic challenge and requires dynamic vascular studies for its characterization. The IGV is considered a benign, low-flow venous lesion with very low risk of bleeding that might cause secondary symptoms mainly due to compression of the adjacent parenchyma.A 12-year-old female patient with non-contributory medical history presented with headache for the last 2 months. Upon admission, her neurological examination was unremarkable. Magnetic resonance imaging (MRI) and computed tomography angiography (CTA) images demonstrated a large varicose dilation of the superficial Sylvian vein, located anterior to the left temporal pole, with no evidence of abnormal arteriovenous connections or tumoral lesions. This finding was considered incidental and unrelated to her symptoms. In this case, we considered that the combination of CTA and MRIs was enough to establish an accurate diagnosis, excluding the need to perform invasive imaging studies. Taking into account these considerations, the patient was managed with conservative treatment and has been followed up for 1 year, remaining asymptomatic.Cerebral IGVs are rare vascular lesions that are treated conservatively when asymptomatic and surgically in the case of rupture or compression of adjacent structures. Given our observation of a high unlikelihood of vascular connections to arteries, and the information obtained with non-invasive imaging techniques such as CTA and MRI was enough to make a clinical decision and avoid the evaluation with invasive procedures.