Abstract The anatomical basis and cognitive profile of diencephalic amnesia remain unclear. We report a two-part study. First, we studied four patients with bilateral medial thalamic infarctions using magnetic resonance imaging (MRI) and comprehensive neuropsychological testing. All patients were followed for more than one year. Using a stereotactic method, we plotted the lesions in an atlas delineating the probable structure involved. Second, in two monkeys, using autoradiography, we traced the pathway from the amygdala to the dorso-medial nucleus, paying particular attention to the intra-thalamic course of the amygdalo-thalamic projections.