With the growing awareness of consumers about the need to preserve the environment and the planet they live on, the growth of environmentally friendly products and their consumption in all domains is noticeable. Consumers are increasingly choosing to buy brands that are clearly committed to sustainability. It's clear that selling environmentally friendly products is not only a good business idea - it's also potentially lucrative. Environmentally friendly products are products that meet strict standards on how their production, packaging, delivery, use and disposal affect the environment. Eco-friendly products will have an ecolabel on their packaging to indicate that they meet these sustainability standards. The aim of this diploma thesis is to investigate the theoretical determinants of product sustainability, the application of green marketing of sustainable products and the analysis of the specifics of sustainable product placement, and in the empirical part to perform a comparative analysis of the placement of ecological clothing by Pact and Eileen Fisher. The purpose of the diploma thesis is to point out the importance of consumption of sustainable products and the way in which they are marketed in the context of raising consumer awareness of the need for greater consumption and the stimulation of growth in demand for sustainable products. A comparative analysis of two companies from the field of production and marketing of ecological clothing - Pacta and Eileen Fisher, shows that both are internationally successful and recognized companies that have a positive effect on the environment through their business and for which the generation of profitability is a minor business goal compared to ecological sustainability. The company Pact has a more significantly developed strategy of marketing its ecological clothing through personalized orders, while Eileen Fisher finds her more important involvement in the significant promotion of the company's director herself on raising awareness of the importance of using ecological clothing.