The adoption of sustainable management practices is booming among service companies, whether due to pressure exerted by external agents or the internal perception that not being aligned with sustainability distances companies from clients and puts companies' long-term prospects at risk. However, few studies have examined the combined effect of implementing environmental management practices and corporate social responsibility practices in the tourism sector. By analysing two surveys conducted with the managers of 370 hotels and 176 restaurants and using structural equations, this study concludes that sustainability practices have a direct and significant impact on the company's competitiveness and on the companies' financial results. However, a separate study of the two surveys shows significant differences between the two analysed groups. This article suggests that despite operating in the same sector, hotels and restaurants behave differently regarding sustainability practices, and they achieve significantly different results in their implementation. In addition, by focusing on the tourism industry, a highly competitive sector, this analysis sheds light on whether investing in sustainability is a good strategy for companies to differentiate themselves and survive in complex sectors.