Ecological compensation is commonly employed but rarely evaluated around the world. In order to assess application of the tool in New Zealand, a systematic nationwide review was undertaken. The research used a combination of qualitative and quantitative tools (i.e. a mixed methods approach) to investigate outcomes associated with ecological compensation under the Resource Management Act 1991 and how variation among outcomes might be explained. Three key research components were addressed: compliance, practice and stakeholder perspectives. Compliance The levels of regulatory compliance were assessed in 81 consents and 245 conditions with an overall compliance level of 64.8%. Public organisations (75.5%) were more likely to comply than private companies (65.5%), followed by private individuals (54.7%). Administrative conditions (paper-based) were much more likely to be complied with (82.6%) than non-administrative (action based) conditions (49.6%). There were significant differences in compliance rates across different activities from Agriculture (4.8%) through to Energy Generation (100%), demonstrating the importance of understanding the nature of non-compliance in improving regulatory compliance and enforcement. Practice The recognition of key implementation issues of ecological compensation were investigated based on the ecological exchanges approved in 110 consents. The key implementation issues were (1) equivalency, (2) spatial proximity, (3) additionality, (4) timing, (5) duration and compliance, and (6) currencies and ratios. Most exchanges approved under the RMA were ‘in-kind’ (i.e. broadly similar in type) but that their ecological equivalence was difficult to determine due to poor information. Most exchanges were close to the site of impact (65.5%), and those at a distance were typically the result of aggregated schemes such as mitigation trusts. Most requirements for ecological compensation can be considered to be additional, as there are few other means of compelling ecological restoration or other positive conservation activities in New Zealand. Most ecological compensation (94.5%) was required to be delivered concurrent with or after the activity that was approved with a range of mechanisms used to secure those outcomes. This research also showed that currencies and ratios are rarely used in the determination of ecological compensation. Stakeholder perspectives Semi-structured interviews were conducted with 116 stakeholders from a wide range of disciplines, and demonstrated that while the potential of ecological compensation is well understood and its use is well-supported (96.5%), most stakeholders have significant concerns about implementation. Strong support (87.9%) exists for a more robust and formalized approach to ecological compensation. For ecological compensation to contribute positively to the management of effects on the environment, the exchanges of biodiversity lost and gained must be robust. The present research has demonstrated that the implementation of ecological compensation in New Zealand is falling short of this expectation, and has identified a range of areas for improvement. The significant potential for failure inherent within ecological compensation requires mitigation with policy and practice improvements, and comprehensive follow-up and review of outcomes. Changes in the use of ecological compensation in New Zealand, toward a context that supports more robust exchanges and limits the potential for negative impact of the tool upon ecosystems and species are essential.