【】Objective? Explore the early clinical manifestations, diagnosis, and treatment methods of spontanneous cerebral spinal fluid otorrhea in adults.Methods A 61-year-old adult (Case 1) and a58-year-old adult (Case 2) with SCSFO were analyzed based on literature reviews, including clinical presentations, audiologic and imaging findings, surgical approaches, and prognoses. Results Case 1 presented with long-term bilateral hearing loss, ear fullness, nasal congestion, and rhinorrhea. Endoscopic examination revealed bilateral middle ear effusion, hypertrophy of the inferior turbinate, and purulent discharge in the nasopharynx. Multiple tympanic punctures were performed, with recurrent episodes. After bilateral eustachian tube balloon dilation, bilateral tympanic membrane ventilation tube placement under endoscopic guidance, and endoscopic plasma radiofrequency ablation of the bilateral inferior turbinates, right ear discharge ceased, while left ear continued to have persistent drainage. Cerebrospinal fluid (CSF) biochemical tests confirmed CSF leakage. Cranial base CT and temporal bone MRI identified localized bony defects in the left cranial base. Exploratory surgery via the mastoid approach revealed a partial defect in the mastoid tegmen, which was successfully repaired using auricular cartilage perichondrium and fat grafting.? Case 2 exhibited right ear fullness accompanied by hearing loss. Endoscopic otologic examination identified signs of middle ear effusion in the left ear, with a history of multiple tympanic punctures. Temporal bone CT scan detected suspected defects in the right tympanic tegmen. CSF biochemical tests confirmed CSF leakage. Exploratory surgery via the ear canal approach identified a fistula located in the tympanic tegmen. The defect was successfully repaired with auricular cartilage perichondrium grafting and biological glue sealing.? Follow-up at 2 years for Case 1 and 6 months for Case 2 showed no recurrence in either case. Conclusion SCSFO is rare in adults and is often misdiagnosed as secretory otitis media. Laboratory tests for middle ear effusion can aid in diagnosis, while cranial base CT and MRI are crucial for diagnosing and determining the fistula location as well as selecting the surgical approach. Surgery remains the most effective treatment.