AMNESIC agents, such as electroconvulsive stimulation, can cause loss of memory for events that occurred before treatment1. Usually as the interval between learning and convulsive treatment is increased, the resulting retrograde amnesia is diminished1–3. This temporal gradient of retrograde amnesia can sometimes cover several years4. Clinical descriptions of the amnesic syndrome suggest that information about the temporal sequence of events can be more severely impaired than other aspects of memory5,6. Thus, an amnesic patient may describe a past event accurately but be unable to report when the event occurred. We have administered a new remote memory test based on former one-season television programmes to psychiatric patients receiving bilateral electroconvulsive therapy (ECT), and report here that memory for temporal order is markedly affected by ECT. ECT caused retrograde amnesia for order information about programmes broadcast from 1 to ∼7 yr before treatment, but not for programmes broadcast from 8–;17 yr before treatment.