To evaluate the intraocular pressure (IOP)-lowering effect of travoprost in normal-tension glaucoma (NTG) over a 12-month follow-up. Forty-five eyes of 45 patients with unilateral NTG were treated with travoprost (0.004%) once a day for 12 months. Mean IOP and the IOP reduction from baseline were assessed at 0.5, 1, 3, 6, 9, and 12 months after the initiation of the treatment. Adverse ocular event frequency and the frequency of discontinuation of treatment due to adverse events were evaluated. Mean IOP during 12 months of travoprost treatment ranged from 11.17 to 11.82 mmHg, and the mean IOP reduction in relation to baseline IOP from -2.71 to -3.71 mmHg (-18.3% to -25.1%). Mean IOP and IOP changes in the travoprost-treated and control groups were significantly different at every follow-up (P < 0.05 in each case). Both the magnitude (r = 0.6992) and percentage (r = 0.5464) of IOP reductions correlated positively with baseline IOP values. Ocular adverse events were usually mild to moderate and resolved without treatment. Travoprost was well tolerated and significantly reduced IOP in NTG patients. In addition, initial IOP reductions were maintained throughout follow-up. Travoprost was found to be more effective in patients with greater baseline IOP.