Transplantation of neural tissue has been explored as a potential therapy to replace dead or dying cells in the brain, such as after brain injury or neurodegenerative disease. However, survival of transplanted tissue is poor, especially when the transplant recipient is of advanced age. Recent studies have demonstrated improvement of neuronal deficits in aged animals given a diet supplemented with blueberry extract. The present study focuses on the survival of fetal hippocampal transplants to young (4 months) or middle-aged (16 months) animals with or without dietary supplementation with blueberry extract. Results indicate that fetal hippocampus transplanted to middle-aged host animals exhibits poor survival characterized by reduced growth and compromised tissue organization. However, when middle-aged animals were maintained on a diet supplemented with 2% blueberry extract, hippocampal graft growth was significantly improved and cellular organization of grafts was comparable to that seen in tissue grafted to young host animals. Thus, the data suggest that factor(s) in blueberries may have significant effects on development and organization of this important brain region.