OBJECTIVE: To alert otolaryngologists to consider the possibility that bone wax may be associated with cerebrospinal fluid leaks that occur immediately after skull-base craniotomy approaches. STUDY DESIGN AND SETTING: Clinical report from surgical experience in a tertiary care setting. RESULTS: Three patients presented with brisk cerebrospinal fluid leak after craniotomy. Sinus endoscopy revealed bone wax within a small parasphenoid defect in all 3 cases. CONCLUSIONS: Bleeding from areas of the skull base adjacent to the paranasal sinuses during craniotomy can signal a small breach of the skull base. Bone wax may control bleeding from edges of transected bone but also stent the skull-base defect open, preventing fibrin deposition and spontaneous healing and closure. SIGNIFICANCE: Otolaryngologists repairing a cerebrospinal fluid leak after a skull-base craniotomy approach should consider the possibility of encountering bone wax and be able to identify it to better treat their patient.