summary If a patient suffering from retrograde amnesia following a traumatic brain injury develops psychological problems but has no obvious neurological abnormalities, specialists readily conclude that the amnesia must be psychogenic. In this case study it is explained why such a conclusion is debatable. The subject of the study is an 18-year-old patient with retrograde amnesia who was given a long course of psychotherapy because his memory loss was diagnosed as being psychogenic. On subjecting the patient to a thorough neuropsychological examination we found that his amnesia had an organic basis.