Studies from 1973 to 1985 of the effects of benzodiazepines on memory are summarised and reviewed. Anterograde amnesia appears a common effect of all benzodiazepines although its onset and duration vary with the particular benzodiazepine, its dose and route of administration. Memory impairments increase with task difficulty. There is some evidence that partial tolerance to amnesic effects develops with repeated doses of diazepam, but research with other benzodiazepines is inconclusive. Amnesia is in part a by-product of the sedative action of benzodiazepines, although these drugs may also have a specific effect of disrupting the consolidation of information in long-term memory. State-dependent effects are partial and relatively small. Methodological problems are discussed and attention is drawn to the lack of repeated dose studies, of studies with patient populations and with anxious volunteers.