A spinal fluid leak from the intracranial space to the nasal respiratory tract is potentially very serious because of the risk of an ascending infection which could produce fulminant meningitis. Cerebrospinal rhinorrhea typically stems from a complication of head trauma, and fortunately these leaks tend to heal spontaneously. In a smaller percentage of cases, intracranial lesions or congenital osteomeningeal defects are harbored, allowing spinal fluid to enter the nasal cavity, and patients with this condition rarely heal without operative intervention. Succesful repair of a dural defect mandates precise anatomic localization of the leakage site. Although radioisotopes have been a popular method of documenting and localizing a spinal fluid leak, they do not provide the topographic accuracy of intrathecal dyes such as fluorescein. The author not only employs this dye during the preoperative localization of a leak but also uses it intraoperatively to improve visualization of the leakage site and to plan a method of repair. The operating microscope also seems to facilitate visualization of the leak and enables better manipulation of grafts and flaps.