Nuclear sites around the world are being decommissioned and remedial actions are being undertaken to enable sites, or parts of sites, to be reused. Although such activities are relatively straightforward for most sites, experience has suggested that preventative action is needed to minimise the impact of remediation activities on the environment and the potential burden to future generations. Removing allcontamination in order to make a site suitable for any use generates waste and has associated environmental, social and economic drawbacks and benefits. Site remediation should thus be sustainable and result in an overall net benefit. This report draws on recent experience of NEA member countries in nuclear site remediation during decommissioning in order to identify strategic considerations for the sustainable remediation of subsurface contamination - predominantly contaminated soil and groundwater - to describe good practice, and to make recommendations for further research and development. It provides insights for the decision makers, regulators, implementers and stakeholders involved in nuclear site decommissioning so as to ensure the sustainable remediation of nuclear sites, now and in the future.