The purpose of this study is to determine which environmental stakeholders exert more pressure on a firm as well as the degree of cooperation existing between the firm and these groups. In addition, this article analyses how stakeholders´ actions influence the perception of managers about the environment as a competitive opportunity in different sectors. A sequential mixed methods study has been carried out, specifically a QUAL→QUAN design. The first stage (qualitative) is a multiple case study of eight Spanish firms from the primary, secondary and service sectors. The second stage (quantitative) includes a structural equations model for a sample of 239 hotels and 208 manufacturing firms. The findings show that stakeholders´ influence on the managerial perception of the environment as a competitive opportunity depends on the sector analysed. This influence is stronger in the group of manufacturing firms affected by Spain‟s Integrated Pollution Prevention and Control law (IPPC) than in the hotel industry. As for the degree of collaboration between stakeholders and the firm, it is higher among suppliers in the primary and secondary sectors, whereas in the service sector, it is customer participation that has prevailed.