Background: Cataract is one of the biggest causes of blindness. One method to cure it is phacoemulsification surgery. However, this action also has an effect on the body, one of which is the increase in postoperative intraocular pressure (IOP) due to the loss of viscoelastic residuals and blockage of the flow of humor aqueos due to trauma experienced. The increase in IOP can cause clinical manifestations in the form of ocular pain. Purpose: To evaluate the effect of 0.5% timolol to reduce ocular pain in cataract patients post phacoemulsification surgery Design: Experimental analysis with a single blind randomized control trial design. Method: Patients who underwent phacoemulsification surgery were randomly divided into 2 groups, the first group was the control group that received placebo therapy and the second group was the treatment group which received 0.5% timolol therapy. Then on the first and seventh day postoperatively, patients are evaluated for ocular pain experienced by patients using Visual Analog Scale Result: On the first day after phacoemulsification surgery, the control group average VAS was 2.7 ± 0.64 and the treatment group was 2.9 ± 0.85 with p = 0.518. Whereas on the seventh day postoperatively the control group VAS was 1.00 ± 0.84 and the treatment group was 0.4 ± 0.59 with a value of p = 0.013. So timolol 0.5% twice a day reduces pain in cataract patients on the seventh day after phacoemulsification surgery. On the first day there were no significant VAS differences between the control and treatment groups. Significant differences in VAS values only occurred on the seventh day postoperatively. Conclusion: Timolol 0.5% twice daily administration reduced VAS values on the seventh day after phacoemulsification surgery