Aim: To evaluate the influence of topically administered latanoprost, a prostaglandin F<sub>2α</sub> analog, on the corneal epithelial barrier function. Patients and Methods: Twenty-four patients suffering from a glaucoma were enrolled. Ten patients without prior topical antiglaucoma medication received topical latanoprost (0.005%, once daily) for 30 days (monotherapy group); 14 patients receiving topical antiglaucoma medication also received latanoprost (0.005%, once daily) for 180 days (combination treatment group). Before and 30 days after treatment (monotherapy group) and before and 30 and 180 days after treatment (combination group), the corneal epithelial barrier function was measured by a fluorophotometric technique. Results: The fluorescein uptakes in the monotherapy group were 54.6 ± (SE) 7.5 and 57.1 ± 11.0 ng/ml before and 30 days after treatment, respectively (p = 0.81). In the combination group, the uptakes were 101.0 ± 18.3 and 118.9 ± 25.9 ng/ml (p = 0.38) and 93.4 ± 17.5 ng/ml (p = 0.58) before and 30 and 180 days after treatment, respectively. Conclusion: The corneal epithelial barrier function remained intact following the instillation of latanoprost in both groups.