ABSTRACT Background The brain is built up during pregnancy. How it functions afterwards depends on how the expectant mother's diet nourishes it. Walnuts contain significant quantities of polyunsaturated fatty acids (PUFAs) and bioactive phytochemicals, which enhance brain health and function even with advancing age. This study examined the effects of a walnut-enriched diet (WED) on corticohippocampal histoarchitecture and gene expression in rat offspring. Materials and methods Twenty-eight female adult Wistar rats (n= 7) averaging about 185 g in weight were used for this study. After mating, pregnant dams were split randomly into four groups: A (standard rat chow/control), B (WED from GD 0 – PND 21), C (WED from GD 0 – PND 1), D (WED from PND 1 – PND 21). Offspring of dams were sacrificed at adolescence (PND 35), with brain tissues of interest harvested for subsequent analyses. Results We observed no significant correlates in litter size, body, and brain weights across the experimental groups. Histomorphology revealed no distortion in cellular layering and delineation of cells in the PFC and dentate gyrus of both control and WED groups. Nissl staining intensity was enhanced in the offspring of dams exposed to WED versus the control, indicating improved proteostasis. Upregulated mRNA expression of DNMT3a, H2Ax, OPA1, and BDNF was observed in cortical and hippocampal tissues of WEDexposed offspring compared with the control group. Conclusion A diet enriched with African walnuts during early development induced changes predictive of cognitive improvements and enhanced stress-response signalling, plasticity, and neural resilience in rat offspring.