This article focuses on describing the main aspects of the controlling in small and medium-sized companies. The author bases the conclusions long-term research, based on which he maps the distinguishing of the environment of process management of small and medium-sized enterprises from large enterprises and describes the process model based on the principle of management and controlling, which he has long examined and published about. It differs from approaches used so far, particularly in the system based on management accounting. It is also based on a balance between business planning and controlling, which includes risk management. They aim of the article is to highlight the differences between management and financial accounting in a small and medium-sized company, to propose key parameters of strategic and operative controlling and to highlight the results of its failure.