BACKGROUND: Heavy consumption of alcohol has well-documented negative effects on cognition both acutely and chronically. Nevertheless there is increasing research interest in the potential positive influence on cognitive functioning of bioactive dietary components including resveratrol from red wine. OBJECTIVE: This study aimed to compare the acute mood and cognitive effects of resveratrol-enriched red wine with red wine alone during mentally effortful tasks in older individuals. METHODS: Following a double-blind, balanced, crossover design, 16 volunteers (mean age 70.44 years) were tested on two occasions, once following 100 ml red wine; once following the same beverage but enriched with 200 mg resveratrol. They completed six cycles of the Cognitive Demand Battery comprising Serial Threes, Serial Sevens, a Rapid Visual Information Processing task and ratings of mental fatigue. Serum resveratrol and metabolites were co-monitored. RESULTS: There were differential cognitive effects of the two treatments. Compared with red wine alone, resveratrol-enriched wine was associated with significantly enhanced Serial Sevens performance. Conversely red wine alone resulted in better performance during Serial Threes. Serum analysis confirmed absorption of resveratrol metabolites. CONCLUSIONS: These results may reflect increased blood flow from resveratrol and the documented stimulant effects of alcohol at low levels. However the study requires replication with an inert control group.