© 2016 ARS-AAOA, LLC Background: Spontaneous cerebrospinal fluid (CSF) leaks have imaging findings consistent with chronically elevated intracranial pressure, such as empty sella. Meckel's cave is a CSF-filled space that houses the trigeminal ganglion at the cranial base. Our objective in this study was to evaluate “dilated” Meckel's cave as a radiologic sign in patients with elevated intracranial pressure spontaneous CSF leaks and compare the dimensions with those from a control cohort. Methods: Meckel's cave dimensions were measured in patients with spontaneous CSF leaks and documented elevated intracranial pressure. A control group of subjects who underwent magnetic resonance imagine (MRI) scans for unrelated diagnoses were also evaluated. Subjects were included only if suitable MRIs with T2-weighted sequences in the axial plane were available. Results: Sixty-three patients with spontaneous CSF leaks and 91 normal control patients were included in the study. There was significant (p < 0.05) enlargement in all measured dimensions (length and width) for the spontaneous CSF leak group. When evaluating area, spontaneous CSF leak subjects again showed significant enlargement compared with controls (0.81 ± 0.35 cm2 vs 0.52 ± 0.15 cm2; p < 0.0001). Average intracranial pressure measurements were 25.9 ± 9.0 cmH2O. Conclusion: Patients with spontaneous CSF leaks have evidence of enlarged Meckel's caves. Evaluation of Meckel's cave dimensions should be included in preoperative imaging assessment as an additional indicator of chronically elevated intracranial pressure.