Confidential information processing in information systems under conditions of the universal informatization in both stateowned and private companies is an urgent problem. Many operators processing a trade secret or per-sonal data underestimate possible damage caused by the disclosure, deletion or change of confidential in-formation and afterwards become victims either of deliberate criminals or suits of workers whose rights were violated. In such a way, the safety risk assessment of confidential information processed in information systems is a priority trend both for an operator and for a subject of confidential information. As a result of the investigation carried out there was developed a procedure for risk assessment of information systems processing confidential information in which it is possible to define and process a critical group of threats, and also a system for the definition of sufficient and the best set of countermeasures among possible ones. At the intermediate and final stage there is defined a significance of an information safety risk witnessing of measures carried out for the assurance of confidential information safety.