We report an autopsied case of presenile dementia showing neuropathologically abundant neurofibrillary tangles(NFT) without senile plaques(tangle only dementia). A Japanese woman developed memory disturbance when she was 60 years old. At age of 65, her ability to understand deteriorated and euphoria and wandering manifested but neither psychotic symptoms, including hallucination and delusion nor a change in character were observed. The patient was hospitalized at age 66 and a cranial CT scan revealed bilateral moderate atrophy of the cortex and moderate enlargement of the lateral ventricle, especially in the inferior horn. No lobar atrophy was detected. She exhibited an oral tendency and became appallic at her final stage and died at the age of 75. Autopsy showed that her brain weighed 850 g and neuropathological study showed numerous NFT mainly in the entorhinal (trans-entorhinal) region, subiculum, CA1-CA4, dentate gyrus, amygdara, subthalamic nucleus, basal nucleus of Meynert, substantia nigra and locus coeruleus. Severe neuronal loss with gliosis was noted in the temporal lobes including the hippocampal region. No senile plaque was detected in any of the brain regions. There have been some recent reports of patients with abundant NFT with the predominant involvement of the allocortex but no or very little senile plaque. All the patients in the reported cases were very elderly at onset(over 80 years of age). In our case, the onset was presenile and we could exclude any other diseases, that usually present with NFT, and to our knowledge, this is the first report of a presenile dementia with tangles.