A method is described which allows the Golgi-impregnation of neurons within a 'single' section or 'slice' of brain tissue 60-200 micron thick. The method may be combined with a variety of histochemical procedures allowing the identification of specific neural elements in the light-microscope and the subsequent examination of their synaptic relationships in the electron-microscope. The technique makes it possible to control visually the extent of the Golgi-impregnation and allows the re-impregnation of single sections. The procedure is illustrated with examples from the cerebellum, cortex, hippocampus, and thalamus of the rat.