OBJECTIVES: Biosimilars are biotherapeutic products that are similar in terms of quality, safety and efficacy to an already licensed reference biotherapeutic product. The first biosimilar (Omnitrope) received EU regulatory approval in 2006; since then, 14 biosimilars have received marketing authorisation. This study examined the differences in the approaches to reimbursement of biosimilars in countries using HTA to inform decision-making.   METHODS: Four biosimilar medicines were selected to provide sufficient documentation in seven European countries, South Korea and Australia. Regulatory approval and HTA reimbursement decision documents were identified and a qualitative analysis of the processes, recommendations by indication, evidence and key decision drivers was undertaken to explain differences in recommendations across countries. RESULTS: Twenty-one different indications were appraised; 90% of appraisals were ‘recommended’, 9% ‘recommended with restrictions’, and 1% were ‘not recommended’. The Netherlands and Germany accepted ‘clinical comparability’ to the originator as sufficient evidence for automatic reimbursement. Sweden and France were the only countries to appraise and to recommend for all indications. Scotland and Wales recommended all biosimilars but restricted indications in some cases. Agencies accepted the notion of clinical comparability and extrapolation across indications when appraising the evidence. A cost-minimisation analysis and budget impact analysis were key economic decision drivers. A full cost-effectiveness analysis was only requested by NICE. Other factors influential in recommending reimbursement were: lobbying, dual reimbursement processes, and other reimbursement mechanisms. CONCLUSIONS: As the market for biosimilars continues to grow, it is imperative that specific HTA reimbursement processes are developed for assessing biosimilars. This includes further research on how different drug classes should be considered; especially pertinent due to the increase in biosimilars for monoclonal antibody-based drugs, which differ from the product classes (erythropoietin, white blood cell stimulators, growth hormone and insulins) currently dominating the market.