Alzheimer's and Parkinson's diseases are associated with cognitive impairment, although the pattern of cognitive dysfunction is not identical. We investigated the recall and recognition memory of 18 patients with idiopathic Parkinson's disease (PD) and of 32 patients with probable Alzheimer's disease (AD). In the list-learning test using Buschke's selective reminding method, PD patients showed superior delayed recognition memory capability compared to AD patients, whereas immediate recall did not differ in the two groups. In the delayed story recall, PD patients were also able to benefit from rehearsal and probe more than AD patients. The results suggest that PD patients are able to bind information better into long-term storage than are AD patients. This may be due to better function in PD of the entorhinal cortex and hippocampus.