As blood tin concentrations are elevated in Alzheimer's disease and as some low molecular weight organotin compounds are neurotoxic, we have attempted to detect organotins in brain in Alzheimer's Disease. First we measured the concentration of trimethyltin (TMT) in the brains of rats which had been exposed to memory-impairing concentrations of TMT and, as the method of linking hydride generation, cryogenic trapping, gas chromotographic separation and atomic absorption spectrophotometric detection permitted the measurements of organotin compounds when the total tin was greater than 0.2 nanograms, we applied these techniques to human brain tissue, some of which showed neuropathological evidence of Alzheimer's Disease. No low molecular weight organotin compounds were detected in the human brain tissue, but it is possible that tin may be complexed with large organic molecules, the hydrides of which would not be volatile, but which could be identified by liquid chromatography.