1. The present work shows the results on behavior and on biochemical parameters of l-deprenyl (0.1, 5, and 10 mg/kg, p.o.) administered daily for 5 days to rats submitted to global cerebral ischemia. 2. The transient global ischemia was carried out by clamping the animals bilateral common carotid arteries for 20 min. The parameters studied were memory acquisition and memory retention, locomotor activity and thiobarbituric acid reactive substances, as an index of lipid peroxidation. 3. l-Deprenyl treatment significantly improved memory deficits as compared to the ischemic group as measured by the elevated T maze test. A similar result was observed on the passive avoidance test where l-deprenyl improved late but not early memory as compared to the ischemic group. Except for an increased locomotor activity observed in the group treated with 5 mg/kg, no other alteration was detected in this behavioral test. Rats submitted to transient global ischemia (and without l-deprenyl) showed an increase in MDA levels in the hippocampus and the treatment with l-deprenyl (5 or 10 mg/kg) significantly reversed this effect bringing values close to those of the sham-operated controls. A similar profile was observed with nitrite levels. 4. In conclusion, the work showed a significant protective effect of l-deprenyl on memory deficits and lipid hyperperoxidation observed after cerebral ischemia. Possibly, the drug is acting at least in part through its antioxidant activity.