The leather tanning sector in Vietnam is currently growing fast and is becoming an increasingly significant cause of environmental pollution. This study has assessed the environmental impact of the tanning industry in the country, the effectiveness of some of the environmental regulations that govern it and the factors that affect compliance. The study finds that the environmental regulations it focuses on are not very effective at safeguarding the environment - 100% of the tanneries that complied with the environmental regulations had violated waste water and air quality standards. It finds that inspections, production capacity, location of firms, and type of tannery are significant factors that affect compliance. It concludes that improving the environmental performance of Vietnamese tanneries is crucial and makes a number of specific recommendations on how this can be done. These include strengthening regulatory capacity and increasing fines for non-compliance.