Histological examination of liver, kidney, and duodenum of rats fed a diet containing 10% (w/w) dry powdered seeds of Garcinia kola for 6 weeks revealed cellular changes that were not observed in pair-fed control animals. The main cellular changes observed in the rats fed on Garcinia kola diet included vacuolation of duodenal villous epithelial cells, numerous intracytoplasmic vacuoles in hepatocytes, and mild hydropic degeneration in cells of the renal proximal tubular epithelium. These changes are probably due to the flavonoids contained in G. kola seeds.