Benzodiazepine hypnotic medications are widely prescribed for elderly patients, but there is a paucity of information available concerning the residual cognitive and psychomotor (the morning-after) effects of these drugs. We compared two commonly used hypnotics--temazepam and triazolam--in a double-blind, placebo-controlled, single-dose study with community-dwelling healthy elderly with a DSM-III-R diagnosis of primary insomnia. Forty-five subjects over the age of 65 (mean age 72.23, SD = 4.44) qualified for the study. Subjects were randomly assigned to one of five treatment groups (placebo, triazolam 0.125 mg., triazolam 0.25 mg., temazepam 15 mg., and temazepam 30 mg.). Neuropsychological testing was completed at baseline and 12-14 hours after the dosing. Patients were evaluated with a variety of tests that measured attention, concentration, motor speed, immediate memory, and learning of new information. Separate repeated measured analyses of variance were performed to assess the significant changes among the five treatment groups. We found improved performance or no change in all the measures for all medication groups except for impairment of performance on a serial learning task for both high-dose medication groups. The significance of these results and the need for further research in elderly insomniacs is discussed.