Rose Crossin, Lana Cleland, Marta Rychert, Chris Wilkins, Joseph M Boden abstract aims: The availability of legal and illegal drugs is widespread across New Zealand. All drugs have the potential to cause harm to those who use them, and to others. Understanding the nature and extent of these harms depends upon the ongoing and systematic collection of relevant data, which is crucial in achieving the current national policy goal of minimising drug harm. Thus, we aim to describe how information on drug harm is currently collected and measured in New Zealand. methods: This article maps and evaluates harm data within New Zealand, explores data collection methods and timing, and identifies the drugs and types of harm assessed to date. We review large and predominantly administrative datasets that provide a measure of harm, which are collected more than once and/or are updated periodically. results: We highlight a number of key gaps and limitations that exist within the current data landscape, and outline barriers to ensuring greater utilisation. We recommend more frequent data collection, including improved data on harms to others, and inclusion of a wider range of drugs. conclusions: Implementation of these recommendations will improve the understanding of comprehensive drug harm in New Zealand, to guide effective local harm reduction policies and interventions.