30 patients with acute cervico-cephalic syndrome following whiplash injury (neck and head pain, vegetative symptoms and subjective complaints of impaired mental functions) without neurological deficits were investigated in a prospective follow-up of 3 months with neuropsychological examination in the acute phase (x = 5.7 days) and again 6 and 12 weeks after the accident. Attention, concentration, cognition and verbal and visual memory functions were quantified by neuropsychological tests, and changes over the observation period were analysed. In the acute phase all neuropsychological functions were below the individual's normal level. Deficits in attention and concentration recovered within the first 6 weeks. Further recovery within the following 6 weeks were observed in visual memory, imagination and analytic capacity. The capability of verbal memory and abstraction, cognitive selectivity and information processing speed was impaired for a longer time and first recovered after 12 weeks. In conclusion, intraindividual neuropsychological deficits following whiplash injury can be quantified and monitored to show the time course of recovery. Thus in clinical and forensic practice the diagnosis of a pseudoneurasthenic or even "neurotic" syndrome in acute whiplash injury should be made with caution.