Introduction: Brain abscess is a rare life-threatening focal intracerebral infection. The etiology of brain abscess dependsontrauma, surgical intervention, and infection type. In this report, we present a case with brain abscess caused by Prevotella denticola after chronic otitis media infection. Case Presentation: A 27-year-old male patient presented a history of yellowish green ear drainage coloring his pillow for 10 years. One month before admission, he began to suffer from increased headache. He was first admitted to another hospital and treated with ceftriaxone for otitis media. He was referred to our hospital when a brain abscess was detected in cerebral magnetic resonance imaging (MRI). Meropenem and vancomycin treatment was stated empirically because of failure of the previous antibiotic therapy. The abscess was drained through a burr hole on the second day of admission. The aerobic culture of the pus resulted negative; however, black pigmented colonies were detected on anaerobic culture plates. The organism was identified as P. denticola via molecular typing targeting the 16S RNA gene. The postoperative period was complicated by left temporal hematoma that required surgical intervention; left transverse and sigmoid sinuses thrombosis were treated with enoxaparine. Because of the critical condition of the patient, de-escalation was not considered, and the patient received meropenem plus vancomycin for 6 weeks until discharge with complete cure. Conclusions: In conclusion, in spite of usually benign features, chronic otitis media may lead to serious complications such as brain abscess. Every effort should be made for microbiological diagnosis of the causative pathogen(s) for appropriate antibiotic treatment.