While concerns about the environmental effects of marine aquaculture have increased in recent decades, relatively little attention has gone to the measurement of the environmental performance of the sector and its determinants. Nevertheless, such information is required for proposing solutions to improve the production environment and thereby develop the sector in a sustainable way. Focusing on the case of marine lobster aquaculture in Vietnam, this study aims to measure its environmental efficiency by combining a material balance-based data envelopment analysis and meta-frontier data envelopment analysis. A bootstrapped truncated regression analysis is used to link the efficiency scores with characteristics of the farmer, the production and the production environment. The results show that environmental performance in marine aquaculture is influenced not only by the production practices but also by the production environment. On average, there is substantial scope to improve the environmental efficiency of lobster farms in Vietnam and differences between farms are large. Ornate lobster farming has significantly more environmental impact compared to scalloped lobster farming. An inappropriate input mix, in terms of nutrient content, is found to be one of the causes of environmental inefficiency. Moreover, farm size, the existence of other discharge and the distance to the nearest farm significantly affect the environmental efficiency of lobster farms in the study area.