The concept of security data transmission in a mobile diagnostic system composed of the process stations (remote parts of the supervising and therapeutic system) and the operator station (local part of the supervising and therapeutic system) is presented. Process stations are connected to the operator station via radio modems. It allows the installation in mobile facilities. Communication between stations is realized via wireless access points. The examples of the application of the presented issues in mobile systems, as well as the potentially locations of the security risks of transmission are given. The possible options for secure communications are described. The assumptions of the concept of a secure communication in the diagnostic system are explained.