Polyclonal and monoclonal anti-homocysteate antibodies were used with a postembedding immunohistochemical method for light microscopy to localize homocysteate-like immunoreactivity in human primary visual cortex. Densely accumulated dots of diverse size resembling astrocytic processes were labelled in supragranular layers, mainly in layers I and II. Some glial elements intermingled with fibre bundles in the white matter, and astrocytic endfeet in the vicinity of capillaries were also stained. In addition, very few round or elongated neuronal cell bodies in layer IVc were intensely homocysteate immunoreactive. These observations extend to human primary visual cortex previous studies on the preferential localization of L-homocysteate in glia.