The Wnt/beta-catenin pathway has been proposed as promoting intestinal stem cell division. Wnt ligands activate cytoplasmic beta-catenin and increase nuclear translocation of beta-catenin that binds to the Tcf-4 transcription factor. The aim of this study was to investigate beta-catenin expression in the stem cell region of crypts during intestinal growth in rats. Litters of DAxPVG/c rats were humanely killed at 7, 14, 21, 35, and 72 days of life. beta-Catenin and Tcf-4 were quantified by immunoperoxidase staining and image analysis with cumulative signal analysis. Cytoplasmic and nuclear expression of beta-catenin peaked nearly 2-fold at day 14 (versus day 7) of life in the stem cell region of intestinal crypts. Tcf-4 nuclear expression peaked earlier at 7 days and was lower thereafter with age. We conclude that the Wnt/beta-catenin pathway is activated in the stem cell region of intestinal crypts during growth of the small intestine.