PURPOSE: To evaluate the intraocular pressure (IOP) lowering effect of travoprost and brinzolamide within the first 24 h after phacoemulsification cataract surgery. METHODS: This prospective, randomized, double-masked, controlled study comprised 90 eyes of 90 consecutive patients with senile cataract who had uneventful phacoemulsification surgery. Eyes in the first group received travoprost 0.0015%, second group received brinzolamide 1%. Eyes in the third group received balanced salt solution and were used as control. One drop was instilled immediately after surgery. IOP was measured 24 h preoperatively, 6 and 24 h postoperatively. Analysis of variance, Student's-t and chi2-tests were used for statistical analyses. RESULTS: Preoperatively IOP was not significantly different among the three groups (P = 0.653). At 6 and 24 h postoperatively IOP was lower in both travoprost and brinzolamide group when compared to control group (P = 0.018 and 0.015 at 6 h, P = 0.010 and 0.007 at 24 h between travoprost and brinzolamide group was not significant (P = 0.744 at 6 h and P = 0.672 at 24 h). CONCLUSION: Both travoprost and brinzolamide significantly lowered IOP after small incision phacoemulsification cataract surgery within the first 24 h without any side effect.