This paper describes the evaluation of a regional community action intervention to reduce access to alcohol from off-license premises by minors. The intervention focussed on: (1) monitoring alcohol sales made without age identification from off-licenses; (2) utilizing data on alcohol sales for media advocacy and direct contact with alcohol retailers and (3) working with key enforcement staff to encourage increased monitoring and enforcement of minimum purchase age legislation for off-licenses. Evaluation of this intervention used a case study design. Purchase survey data was obtained before and after intervention. Media items were monitored and included pre- and post-intervention phases. Interviews, with key enforcement staff, and document review were undertaken post-intervention. Purchase survey data showed a significant decrease (p < 0.05) in sales of alcohol made to young people without age identification pre- and post-intervention. Pre-intervention: 60% of visits resulted in a sale made without age identification; post-intervention this proportion was 46%. Principal component analysis of newsprint media indicated increased coverage of items advocating improved age checking for off-licenses following intervention. Interview data and document review indicate that some enforcement staff in the region implemented increased enforcement strategies including, controlled purchase operations and increased visits to off-licenses due to the intervention. Evaluation findings indicate that collaborative and intersectoral community action interventions implemented regionally can be effective in redirecting resources to achieve preventive outcomes at a population level.