AIM: To observe the effects of topical 5-fluorouracil (5-FU) application on the rabbits corneal limbus. METHODS: 5-FU was applied topically to the corneoscleral region of rabbits' eyes. The animals were sacrificed immediately or 7, 15, 30 and 60 days later, and tissues were submitted to histological examination. RESULTS: All animals presented corneoscleral deepithelization close to the site of application during the immediate postoperative period, whereas on the 4^th postoperative day ulceration was no longer present. Histological examination showed absence of epithelium and slight edema. After one week(G2), 2 animals presented epithelial defects, thickened epithelium with larger basal cells and loose chromatin, and slight subepithelial edema. The remaining groups showed no alterations. CONCLUSION: The 5-FU topically applied on the corneoscleral limbus postpones the epithelization.