As environmentally sustainable practices are becoming popular in the hotel industry, their impact on efficiency is an important issue. To investigate the performance of hotels in this context, we use data envelopment analysis (DEA) double bootstrap approach to firstly assess the technical efficiency and its determinants of a sample of medium and large scale hotels in Sri Lanka for the period 2010-2014. Secondly, we evaluate the impact of a number of explanatory variables in determining hotel efficiency. The results reveal that the average technical efficiency is 61% with the maximum being 71.5% and the minimum 46.8%. The results conclude that being environmentally responsible enhances the efficiency of hotels, specifically in terms of improving energy efficiency and waste management. Water consumption is shown to have a contradictory result in relation of improving efficiency. Finally, we estimate the bootstrapped Malmquist productivity index to examine the level of productivity in the Sri Lankan hotel industry. The results of this study provide hotel operators and government with insights into the nature of competitive advantage which can assist them with strategic decision making to improve the technical and environmental management of hotels.