The master thesis focuses on investigation of optional demand for services in environmental audits in relation to due diligence matters. This is performed especially for the Austrian market. An Environmental Due Diligence checks the subject environmental during merger & acquisition transaction. An environmental risk assessment aims at the identifying the relevant environmental risks and their monetary evaluation related to a company. The basic of information of the market analysis - Environmental Due Diligence collected proper studies which including the answers of more than thousand sent questionnaires. With the results of the studies, the market volume and the market potential was estimated by their corresponding space. A short description of the Environmental Due Diligence, an excurse about the adviser liability and the future prospects of the market for the Environmental Due Diligence completed the work.