Decision Support System (DSS) in a firm is a vital part of it`s entire information system. It can be defined as computer technology solutions that can be used to support complex decision making and problem solving. It`s goal is to provide quality informations to the user due to support in decision making where informations are the result of real data processing. Decision Support Systems in management combine a vast number of methods and they focus their activities on problem solving area of business management. The survival and regional/global competitiveness of today`s companies, in the turbulent business environment, depends on getting the right information in the right time. DSS tools like "data warehouses", "knowledge warehouses", OLAP (On-Line Analytical Processing), "data mining", Web-based DSS enable finding and filtering of data into much needed information. Application of DSS would make croatian firms much competitive on regional as well as on global European market.