Ecotourism represents a modern form of tourism that accepts the principles of sustainable development and the adequacy of the conditions of tourist destinations. The environmental awareness of all parties participating in tourism, objects, and subjects of tourism determines the development of ecotourism. Ecohotels, or “green hotels”, as an integral part of ecotourism, represent tourist accommodation facilities that have the “The Flower” certificate, their business activities minimize the impact on environmental quality. The management of ecohotels therefore implements programs and measures determining sustainable competitiveness at the local, regional, and supra-regional levels in the business in interaction with reducing the carbon footprint, water consumption, energy consumption, and waste production. They also support the use of recyclable materials and bio-products and the introduction of environmental management respecting the principles of green management in all areas of the tourism business. The competitiveness of ecohotels is in interaction with the willingness of tourists to use their pro-environmental services. The presented study is focused on the willingness of tourists to use the services of ecohotels, with an emphasis on identifying an effective strategy for supporting the development of ecotourism in the Slovak Republic. The study concentrates on the willingness of tourists to use ecohotels as part of their tourist activities based on a questionnaire survey. The study identifies the factors of strengths and weaknesses as well as the opportunities and threats of the use of ecohotels by tourists in supporting the development of ecotourism. Through the exact quantification of the weights of individual factors in terms of Saaty’s matrix and a SWOT analysis, an effective strategy for the use of ecohotels in supporting the development of ecotourism is defined. In recent years, the stimulation and use of tourists’ interest in environmental quality, with an emphasis on reducing negative impacts on the environment, has resonated; thus, a model of effective marketing strategy is presented.