We first reported ubiquitin‐positive tau‐negative intraneuronal inclusions in the hippocampal granular cell layer and entorhinal cortices in patients with amyotrophic lateral sclerosis (ALS). We then found that those inclusions occur frequently in patients with presenile dementia and motor neuron disease. The ultrastructure of the inclusions consists mainly of granules with a few filaments. In 2006, TDP‐43 was identified as a major component of the inclusions specific for frontotemporal lobar degeneration and ALS. Here, we review the current knowledge regarding ubiquitin‐positive tau‐negative intraneuronal inclusions.