OBJECTIVES To analyze the cost-effectiveness of temozolomide in the treatment of newly diagnosed glioblastoma multiforme versus radiotherapy alone from the Mexican health care perspective METHODS A cost-effectiveness analysis was performed based on a Markov model, with three health states: initial, disease progression and death. This model allowed us to compare the expected outcomes and costs associated with temozolomide compared with radiotherapy alone for a synthetic cohort of patients aged ≥55 years over a 5-year period. The model cycles every six months and continues until all patients die. The probabilities of transition between health states were obtained from the literature. Costs were expressed in 2008 US dollar. Outcome estimates included the incremental cost-effectiveness ratio (ICER) and cost per life-year (LY) gained. Costs and health outcomes were discounted at 5%. Second-order Monte Carlo simulations were undertaken in which values were randomly drawn from distributions of these parameters. RESULTS The accumulated discounted effect is 1.03 LY per patient receiving temozolomide compared to 0.93 LY for radiotherapy alone. Total lifetime medical cost was US$31,698 for temozolomide vs US$30,715 for radiotherapy alone. The incremental cost-effectiveness of temozolomide was US$983 per life year gained. There is a 70% probability that temozolomide is cost-effective at a US$10,000 per life-year saved threshold and a slightly more than 95% probability of being cost-effective at a US$18,000 per life-year saved threshold. CONCLUSIONS Results from these analyses suggest that in the Mexican setting, use of temozolomide in place of radiotherapy alone for treatment of glioblastoma multiforme is likely to be cost saving. These conclusions are supported by the use of conservative assumptions and sensitivity analyses.