This study examines hippocampal CA1 cells from brains of aged humans, with and without Alzheimer's disease, for hyperphosphorylated tau and aluminum during early neurofibrillary tangle (NFT) formation and growth. A very small proportion of hippocampal pyramidal cells contain cytoplasmic pools within their soma that either appear homogeneous or contain short filaments (i.e., early NFTs). The cytoplasmic pools are aggregates of an aluminum/hyperphosphorylated tau complex similar to that found in mature NFTs. The photographic evidence presented combines with existing evidence to support a role for aluminum in the formation and growth of NFTs in neurons of humans with Alzheimer's disease.