Forty patients, in two age groups, undergoing gastroscopy, received intravenous midazolam as the sole pre- medication. Mean ages were 35 (range 19-47) and 65.5 (range 53-75) and mean dosages 4.52 and 5.82 mg, respectively in the two groups. Neuropsychological testing pre- and post-medication comprised the Rey auditory verbal learning test (RAVLT), word association test, digit span and face memory test. The elderly group gave significantly more false-positive responses on recognition recall on the RAVLT and had significant impairment of reverse digit span. Following midazolam, in both age groups there was a significantly reduced rate of verbal learning and a marked deficit in delayed free recall coupled with substantial preservation of recognition recall. Word fluency and forward digit span were not affected. There was an increase in false-positive responses for face memory. These findings are consistent with a specific processing deficit affecting the acquisition of episodic long-term memory.