Background and Objective: Intraocular pressure (IOP) elevation is a major risk associated with glaucoma. Timolol is the most frequently used drug in the management of open-angle glaucoma (OG). The objective of this study was to compare the IOP-lowering effects of bimatoprost (BM) with timolol in a Chinese population with OG. Methodology: A total of 480 eyes of indoor patients suffering from OG (study group) and 50 normal eyes of indoor patients not suffering from OG (non-study group) were included in the study. The eyes of the treatment, control and non-study groups were treated with one drop of 0.03% w/v BM once daily, 0.5% w/v timolol maleate (TM) twice daily and water injection twice daily for 3 months, respectively. The lOP was measured at baseline and at 2, 6 weeks and 3 months of treatment. Conjunctival hyperemia, eye irritation, ocular hyperemia, foreign body sensation in eyes, corneal staining, heart rate and systolic and diastolic blood pressures were determined for the study group between baseline and 3 months of treatment. SPSS was use to analyze the data. Analysis of covariance was used to show better efficacy of BM compared with TM. One-way analysis of variance (ANOVA) and the Wilcoxon test were used for insignificant differences of ocular and systematic adverse effects. Results: There was a significant difference in IOP at baseline compared with the end of 3 months of BM (p = 0.00041) and TM (p = 0.0091) treatments. There was no significant difference between conjunctival hyperemia, eye irritation, ocular hyperemia, foreign body sensations in eyes, corneal staining, heart rate and systolic and diastolic blood pressures between baseline and at the end of 3 months of patients treated with BM. There was a significant difference for eyes reaching and maintaining an IOP<18 mmHg between the control group and the treatment group (p = 0.0478). Conclusion: The BM was more effective than timolol in lowering IOP over 3 months of treatment in open-angle glaucoma patients.