Ethanol exerts damaging effects on gastric mucosa and delays ulcer healing. To investigate the effect of ethanol on the wound repairing process, we used a wound repair model using primary cultured gastric mucosal cells. A confluent monolayer gastric mucosal cell sheet consisting mainly of mucous cells was wounded to make a cell-free area of constant size. Cell-free area was restored with time after wounding and monitored every 12 hr using a computer image analyzer to observe epithelial cell restoration quantitatively in the presence and absence of ethanol (2.0%). It was found that, although the control wound was completely repaired in 36 to 48 hr, the group treated with 2.0% ethanol showed a significant delay of repair. In the control, 5-bromodeoxyuridine-positive cells appeared around the wound in 24 to 36 hr. In contrast, the group treated with 2.0% ethanol showed no 5-bromodeoxyuridine-positive cells during the experiment. In conclusion, 2.0% ethanol retarded the repair of gastric mucosal restoration by inhibiting the initial gastric cell migration, followed by inhibition of proliferation of cells.