Several experiments are reported which concern the possible role of long-term occupational exposure in the etiology of dementia. A case study of a male with memory impairment thought to be due to Alzheimer's disease is reported. Neuropsychological testing revealed impairments in short-term memory, which gradually cleared over months. Analyses uncovered extremely high serum levels of a solvent (perchlorethylene) this individual had used for decades in a dry-cleaning business. A case-series is also reported in which four individuals with similar patterns of neuropsychological performance were noted to share occupational exposure to metal vapors. The results of a preliminary case-control study are also reported in which an increased incidence of long-term occupational exposure to metals and solvents was noted in patients with Alzheimer's disease. These results suggest that the role of long-term occupational exposure needs to be thoroughly investigated in patients diagnosed with Alzheimer's disease and other neurological disorders.