Abstract Objectives Endoscopic endonasal approach (EEA) procedures are inherently contaminated due to direct access through the nasopharyngeal mucosa. The reported rate of postoperative meningitis in EEA procedures is between 0.7 and 10%. Lumbar catheters are used in EEA surgeries to prevent cerebrospinal fluid (CSF) fistulae, but their use is associated with increased infection rates. This study investigated whether there is a difference in rates of postoperative meningitis based on lumbar catheter (LC) utilization. Methods We performed a retrospective review of consecutive patients who underwent EEA surgeries between January 2016 and March 2023 at a single institution (Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia). Main Outcome Incidence of meningitis following EEA surgery with lumbar catheter. Results Seventy-two patients were enrolled, median age was 44 years, and 53% were female. The most frequent surgery performed was craniopharyngioma 46% (26 patients). A LC was used in 28 patients. Meningitis was diagnosed in 11 of 72 patients (15.2%), being higher in the LC group (10 patients). The odds ratio for the development of meningitis in the presence of an LC was 23.38 (95% confidence interval, 2.77–123.78; p < 0.004). There was no statistical difference in the reported incidence of meningitis when CSF leak was present. Conclusions This study demonstrates an extremely high incidence of meningitis (36%) following EEA procedures when an LC is used. The incidence of meningitis was not significantly associated with CSF leak in our cohort.