Background Brain abscesses often present with headache, altered state of consciousness, and/or fever. Depending on their location, they may present with other clinical manifestations. Gerstmann syndrome, characterized by acalculia, agraphia, digital agnosia, and right-left confusion, occurs classically with lesions of the dominant parietal lobe. Case Description A 50-year-old immunocompetent female presented to the emergency department with seizures, headaches, and visual hallucinations. Brain magnetic resonance imaging revealed a right space-occupying lesion causing a mass effect consistent with a brain abscess. The patient was promptly started on ceftriaxone and metronidazole, followed by successful surgical drainage of the abscess. Cultures confirmed an infection with Streptococcus intermedius . During follow-up, the patient exhibited symptoms of acalculia, agraphia, digital agnosia, and right-left confusion, consistent with Gerstmann syndrome, attributed to significant postoperative edema. Although these cognitive sequelae showed partial improvement over time, they substantially impacted the patient’s functional abilities and psychological well-being. Conclusion Gerstmann syndrome is traditionally associated with lesions in the left angular gyrus. However, in our case, the lesion was located on the right side. Interestingly, there is only one other documented case of Gerstmann syndrome linked to a brain infection in the medical literature. Furthermore, our patient presented without the typical risk factors for brain abscesses, such as immunosuppression, an identifiable infectious source, or epidemiological connections commonly associated with this pathogen. This case highlights a rare and impactful condition, significantly affecting the patient’s quality of life while also contributing valuable insights to the understanding of this uncommon neurological syndrome.