OBJECTIVES: Economic evaluations play an important role in reimbursement decision-making by government agencies such as the pan-Canadian Oncology Drug Review (pCODR) and the United Kingdom National Institute for Health and Care Excellence (NICE). In last decade, many new therapies have become available for the treatment of relapsed and refractory multiple myeloma (RRMM), with more drugs in development. To inform and improve the designs of RRMM economic evaluations, a critical review of pCODR and NICE health technology assessments in RRMM was conducted.  METHODS: A targeted search of the pCODR and NICE websites was performed to identify previous RRMM economic evaluations since 2007. Details of the modelling methods were extracted, including model structure, comparators, data sources for clinical effectiveness, survival extrapolation approach, time horizon, and model assumptions. Critiques from pCODR and NICE were also extracted.  RESULTS: Four (one pCODR and three NICE) evaluations were identified. The drugs evaluated included lenalidomide (RRMM with at least one prior treatment), bortezomib (RRMM with one prior treatment), and pomalidomide (RRMM previously treated with lenalidomide and bortezomib). Model structures used included partitioned survival model, semi-Markov model, and discrete-event stimulation model, all of which are considered appropriate. Since crossover was allowed in the key clinical trials used to inform the clinical effectiveness, external data were used to adjust the survival estimates in all four economic evaluations. Main issues criticized by pCODR and NICE were inappropriate comparators, need for shorter analysis timeline (five vs. ten years), methods used for indirect comparison, inappropriate extrapolation of clinical benefit beyond trial period (sustained effect vs. none), not including costs and disutility of adverse events, and validity of health state utility values.   CONCLUSIONS: The findings of this study suggest that most problems identified by pCODR and NICE could be avoided if the submissions conform to the methods guidance set by the reimbursement authorities.