This article presents a case study indicating that "Herpes simplex" virus (HSV) encephalitis may cause permanent learning disabilities due to damage to the temporal lobes as it discusses the results of a case study extending over 10 years to determine the long-term effects on both the anatomy of the brain and the intellectual functioning of the subject. Magnetic resonance imaging (MRI) scans were taken of the subject during the initial HSV encephalitis infection and subsequently six months after recovery. Follow-up MRI scans were taken 10 years later. At this time the Senior South African Individual Scale-Revised IQ test was administered to determine any residual neuropsychological impairment due to HSV encephalitis infection. Follow-up MRI analysis indicated permanent bilateral necrotic areas in the medial temporal lobe, while the IQ test revealed marked impairment of the short-term memory, verbal memory, visual memory, visual scanning abilities and gestalt formation, which can be ascribed to temporal lobe lesions.