The article deals with the marketing control system from a theoretical and practical viewpoints. It is aimed at chosen tools of the marketing control system and their theoretical aspects as well as practical using in the terms of firms. The authors opinion is that firms usually do not create adequate marketing control systems despite the necessity to monitor, control and analyze marketing activities and the marketing performance. Marketing audit has to be recognized by authors as the key tool of the marketing control system. Due to the fact that the marketing audit enables to review the whole marketing system, it acts in this hierarchy as a system of early warning. It also serves to ensure the control function of marketing controlling. The restrictions during the realization of marketing control system including its key tool the marketing audit are mostly related to a lack of understanding or to the underestimation of marketing, or to a wrong and/or slow approach to its establishment.