Late onset psychiatric disorders are often associated with organic factors, either medical or neurological. First manic episode in old age is rare. We hereby report an elderly patient with first manic episode, who was investigated in detail, but no organic factors were found. A 81-year-old male patient with a history notable for hypertension was presented with complaints of logorrhea, irritability, insomnia (3 hours per day), sleep needs decrease, increase in sexual desire, excessive eating, giving financial support for unrecognized people, excessive spending money during the last fifteen days. He was hospitalized with the initial diagnosis of mania. His vital signs were unremarkable and neurologic examination was normal. He could not adapt to the mini-mental test. Routine blood biochemistry tests were normal. Considering the organic etiology, cranial MRI and EEG was performed for differential diagnosis. Senile cerebral atrophy on MRI was detected and diffuse irregular ground EEG activities consisting of fast rhythm were revealed. According to the history (taken from his family) and the investigations, dementia syndrome was excluded. Patient’s complaints were evaluated as manic episode. He had had an attack of depression in her fifties. Based on the findings of all these investigations, the patient was diagnosed as having the manic episode of bipolar disorder. Valproic acid (500 mg/day) was started. After 10 days, the dose of valproic acid was increased to 1000 mg. After 3 weeks, sleep duration and excess of speech returned to normal was observed. Our case highlights the fact that primary psychiatric illnesses could occur at late age. New onset mania in older adults is commonly attributed to a secondary cause. Therefore, in elderly cases of mania and hypomania, organic causes should be carefully reviewed.