Transient global amnesia (TGA) is one of the most striking syndromes in clinical neurology. Despite several new hypotheses concerning TGA pathogenesis-including psychological disturbances, personality traits, and hypoxic-ischaemic origin associated with venous congestion in memory relevant structures or small vessel changes-there is no consensus about the cause. New imaging techniques, particularly diffusion-weighted imaging, open up new insights into the location of TGA pathology. Studies with dynamic venous duplex sonography confirmed the importance of jugular-vein-valve insufficiency. We review these new findings and their implications for a better understanding of this remarkable syndrome. Although we still do not have all the answers, the use of new imaging modalities, neuropsychological findings, and epidemiological data may in future help to unravel the origin of TGA.