Emergency departments are at the forefront of dealing with the harmful effects of alcohol consumption. ED alcohol-related presentation data is not routinely collected in patient data sets. I will describe the outcomes of the ACEM Alcohol Harm (AHED) project. For the first on a national scale the project quantified the level and effect of alcohol harm presenting to emergency departments (EDs) in Australia and New Zealand. Over 100 EDs and more than 2000 ED clinicians have been involved. AHED provided an evidence base to advocate for measures to reduce alcohol harm I will demonstrate by how using evidence and anecdote clinicians are power witnesses and can influence culture and policy change.