L-2-hydroxyglutaric aciduria (L-2 HGA) is a rare, neurodegenerative, slowly progressing and autosomal recessively inherited metabolic disorder. The disease progresses with mental retardation, behavioral disorder, ataxia, extrapyramidal signs and epileptic seizures. Diagnosis is made by detection of increased levels of L-2-hydroxyglutaric acid in urine, plasma or cerebrospinal fluid. In this report, we presented a 13 year old male patient diagnosed with L-2 HGA and had seizures, intellectual disability, attention deficit hyperactivity disorder (ADHD) symptoms and failure in school performance. Here we discussed this rare disease with ADHD symptoms and the response to atomoxetine treatment.