OBJECTIVE: To establish the extent to which existing sustainability indices provide pertinent and transparent evidence of the environmental and social impacts of health technology providers. METHOD: A search was undertaken to identify a comprehensive list of sustainability indices for study. For each of these the following criteria were identified; target constituency, specific environmental or social domains being measured, criteria for inclusion, data sources and ranking or scoring methodology. RESULTS: The majority of indices were found to be focused on the needs of investors rather than purchasers. The indices either measured specific environmental or social domains such as carbon efficiency, water risks and social impacts, or provided a broader measure of sustainability by combining environmental, social and governance issues together in a single metric. Incorporation within an index often required inclusion in pre-existing non sustainability criteria against which additional sustainability measures were applied. Data used within the indexes reviewed were found to have been derived from publically available sources such as websites and company reports, or from data submitted by the organisations under evaluation to rating research groups. Few of the indices published a level of methodological transparency that could provide sufficient visibility in order to understand how they are derived. CONCLUSION: There remains a latent need among purchasers for a verifiable method of measuring sustainability of providers. In order for a sustainability index to provide utility in the comparison of health technology providers the following criteria must be met; The index should be open to all Health Technology providers, methods used by the index to measure performance should be transparent. None of the current sustainability indexes reviewed fulfilled these criteria. Further study is needed to identify the environmental and social domains of importance to purchasers and the best approach for deriving this data.