OBJECTIVES: The objective of this study is to calculate and compare the costs and costs per PFS and OS for first line CLL treatment regimens in Mexico. METHODS: Relevant treatment regimens were selected based on KOL input and data availability.  Treatment regimen costs were calculated using the dose, number of doses per cycle, and number of cycles per regimen from published clinical trials.  Drug acquisition and administration costs were obtained from IMSS.  Administration costs were applied once per treatment day, regardless of the number of drugs administered.  Progression-free survival (PFS) and overall survival (OS) benefits for each regimen were calculated by applying hazard ratios for PFS and OS from a recent network meta-analysis to the median PFS and OS reported for chlorambucil.  Cost/ benefit ratios were expressed as the regimen cost per month of PFS or OS. RESULTS: Regimens assessed were chlorambucil, fludarabine, fludarabine+ cyclophosphamide+ rituximab (FCR) and cyclophosphamide+doxorubicin+vincristine+prednisone (CHOP).  Costs were estimated in 2012 Mexican pesos.  The regimen cost for chlorambucil ($3,101) was less than fludarabine, FCR and CHOP ($50,430, $525,481 and $105,246, respectively).  Only FCR and CHOP incurred administration costs.  The hazard ratios for OS and PFS showed FCR was the most effective treatment versus chlorambucil (0.24 and 0.73, respectively). The cost/PFS benefit ratio was most favorable for chlorambucil ($352/month) versus fludarabine, FCR and CHOP ($4,757, $14,318 and $18,145, respectively).  Chlorambucil also had the lowest cost/OS benefit ratio ($39/month) versus fludarabine, FCR and CHOP ($639, $4,865 and $1,441, respectively).  CONCLUSIONS: Chlorambucil was the least costly of the Mexican CLL treatment regimens assessed in absolute terms and per benefit.  However, there is a need for a CLL treatment that provides greater efficacy in terms of PFS and OS than chlorambucil, but costs less than FCR.  Future studies should focus on the incremental cost-effectiveness of new regimens for this indication.