We examined the effects of thermal injury on intestinal epithelial cell proliferation and death. We recorded histologically identifiable mitotic and apoptotic crypt cells in relation to cell position after a 60% full thickness cutaneous thermal injury in the rat. The injury significantly reduced mitosis (0.53 ± 0.11 vs. 1.50 ± 0.70, P < 0.05) at cell positions 4-6, stem cells, 6 h after injury. A similar reduction in mitosis (1.13 ± 0.59 vs. 3.50 ± 0.80, P < 0.05) was observed at higher cell positions 7-9 12 h after injury, indicating a positional cell shift. In addition, a significant increase in the number of apoptotic bodies occurred at cell positions 7-9 (2.32 ± 0.87 vs. 0.13 ± 0.22, P < 0.05) and 10-12 (2.2 ± 0.12 vs. 0.00, P < 0.05) 6 h after injury. Thermal injury-induced alterations in mitotic and apoptotic activities were transient since crypts recovered with a moderate increase in mitotic activity 24 h after injury. In control and thermal-injury rats 24 h after injury, crypt cell mitosis and apoptosis did not differ significantly. This demonstrates that cutaneous thermal injury causes a transient suppression of mitosis as well as induction of apoptosis in a cell position-dependent manner in the small intestinal crypt.