OBJECTIVES: Brazil and Mexico present an attractive opportunity for biosimilar manufacturers. The majority of patients in these key Latin American markets rely entirely on government-sponsored healthcare. These public healthcare systems continually strive to limit any premium costs in favor of increasing their suboptimal coverage, particularly of biologics for oncology. This study explores the expected impact of more cost-effective biosimilar alternatives on coverage and prescribing for key oncology indications in Brazil and Mexico. METHODS: Across Brazil and Mexico, 100 medical oncologists and 60 hematologists were surveyed regarding their views on biosimilars for breast cancer, colorectal cancer, and Non-Hodgkin’s lymphoma, and on current and expected biologics prescribing patterns. Additionally, 8 payers who influence reimbursement at a national or regional/institutional level were interviewed. RESULTS: Up to 41% of biologics-eligible public patients with a given tumor type do not currently receive a biologic, according to surveyed physicians in Brazil and Mexico. Respondents largely attributed low access to limited coverage for oncology biologics. Surveyed physicians and interviewed payers anticipate improved access to biologics upon biosimilar launch and an overall reduced burden from oncology biologics to the healthcare systems. Although surveyed specialists indicate some initial caution regarding the bioequivalence of biosimilars, they nevertheless foresee widespread biosimilar uptake. In Brazil’s public sector, for example, respondents expect that 70% of Herceptin-eligible breast cancer patients will receive biosimilar trastuzumab. CONCLUSIONS: Oncology biosimilars should find fertile terrain in Brazil and Mexico. Automatic substitution in the public sector is likely, although interchangeability regulations are currently under discussion in both markets. Cost-effectiveness combined with pharmacovigilance and robust long-term safety data will play a major role in the continuous uptake of biosimilars versus brands, with the latter securing reasonable market share only if priced competitively.