Objective To evaluate age, gender and disease-specific trends in ED for mental health presentations over 15 years. Methods The study population consisted of residents of metropolitan Perth, Western Australia, presenting to Perth ED between 1 July 2002 and 30 June 2017. Population rates of mental health-related ED presentations per year were calculated. Results Rates of mental health ED presentations are significantly increasing in the working-age population for those with stress and anxiety-related diagnoses, particularly in younger females, and also for alcohol-related presentations for those aged 10-49 years, particularly in males. Conclusion The present study demonstrates that increased rates of mental health-related ED presentations are driven by increased rates of presentation for stress and anxiety-related and alcohol-related presentations in both genders across the working-age population.