The effect of stimulation on diffusion characteristics of electrically stimulated neural tissue was examined. Bullfrog nerves and spinal cords were excised and stimulated electrically during magnetic resonance imaging, and the apparent diffusion coefficients (ADCs) of water parallel and perpendicular to the long axes of the specimens were mapped with and without stimulation of the tissue. Electrophysiological recordings were used to determine the viability of the tissue after each experiment. No stimulus-related ADC changes were observed in either the peripheral nervous system or the central nervous system tissue. These experiments may help to define further the nature of previously reported ADC changes in stimulated neural tissue in situ.