OBJECTIVES: The purpose of this study was to compare the intraocular pressure (IOP) - lowering efficacy and cost-effectiveness of Lumigan (Bimatoprost) versus Xalatan (Latanoprost) in glaucoma patients. METHODS: A Markov model was developed to compare the cost-effectiveness of Lumigan initiated treatment with Xalatan initiated treatment in the context of the French Health care system. The model uses a timeframe of one year and data from published randomised clinical trials, which included a total of 249 patients. Patients were allowed to switch medication up to a maximum of two times if target IOP was not met or adverse events occurred and each switch was associated with a physician visit (cost: €23.00 each). Drug costs used were €20.10 for Lumigan and €17.67 for Xalatan. A probabilistic analysis was performed using 1000 Monte Carlo simulations. The primary outcome measures were the number of months patients spent at IOP < 17mmHg and the cost per month at IOP<17mmHg. Sensitivity analyses were conducted varying the target IOPs. RESULTS: More patient months at IOP < 17mmHg were achieved by patients on Lumigan versus Xalatan initiated therapy (9.7 versus 9.3; P <0.05). Lumigan initiated therapy was also associated with fewer annual physician visits per patient (5.14 compared to 5.48; P <0.001). The cost per patient per month at IOP < 17mmHg was €41.96 for patients on Lumigan compared to €44.60 for those on a Xalatan initiated therapy. The results of the sensitivity analysis determined that at target IOPs of 14 to 17 mmHg there was a lower average annual treatment cost per patient for Lumigan initiated patients. CONCLUSIONS: Lumigan initiated treatment is more cost-effective than Xalatan initiated treatment at target IOPs between 14-17mmHg.