OBJECTIVES: Mexico and Brazil have well-developed pharmaceutical pricing systems, with an increasing trend towards use of Health Technology Assessment in access decisions. However, there are significant differences in the prices of innovative medicines in the two countries. The object of the study is to clarify to what extent local decision making criteria can account for these discrepancies and therefore which evaluation mechanisms may have international relevance. METHODS: Secondary research was carried out to identify prices in Brazil and Mexico for 5 patented oncology medicines. A rating scale was then devised with the following decision domains for pricing and reimbursement: international referencing; cost-plus analysis; economic evaluation and budget impact; innovation; unmet needs; therapeutic referencing; negotiated agreements; demand side controls; and societal benefit. In primary research 4 senior stakeholders in Brazil and Mexico were asked to rate the importance of these domains in access decisions, and provide a rationale.  RESULTS: Decision criteria in Mexico and Brazil reflect the historical origins of their respective health systems, but recent developments reflect a centralising trend in decision-making in both countries. This suggests that economic evaluation will increasingly determine access in both countries but pricing criteria will remain different, notably due to the greater role of price negotiation in Mexico. CONCLUSIONS: The mix of empirical and context-based decision criteria in Brazil and Mexico represent valuable alternative models for other countries, such as the UK National Health Service (NHS), which is currently contemplating a move towards “value-based pricing” for pharmaceuticals. In particular, Mexican and Brazilian evaluation mechanisms may inform future considerations of therapeutic innovation in the UK.