Fungal infections are associated with the lowest incidence of post-operative infection following renal transplantation. These infections, however, are associated with a high mortality rate. A 58-year-old man who had received a kidney transplant presented with confused mental status. A brain computed tomography (CT) scan showed a 5.4 cm-sized, septate and thin-walled ring-enhancing lesion. The patient underwent aspiration and drainage of the brain lesion. Aspergillus fumigatus was stained in cultures of the aspirated material. Following surgery, the patient was treated with voriconazole for four months. After four months of anti-fungal treatment, the size of the brain abscess was decreased and serum creatinine was 1.5 mg/dL. Here, we present details of the case, which showed a favorable outcome with the combination of early surgery and voriconazol administration.