Abstract:The role of ICT system's user should be taken into consideration when developing different information security solutions because user, as its constitutive element, can significantly affect overall system security with his/her potentially risky behaviour depending on the level of user's security awareness. In this paper authors propose risk assessment approach of ICT users' behaviour based on the evidential reasoning technique. Performance testing was compared using combination of cluster analysis and discriminant analysis while empirical analysis was conducted on the total of 627 e-mail users grouped regarding gender, age, technical background knowledge and level of experience. Assessment methodology used in this paper has proven to be well suited for evaluation of users' awareness and identification of their potentially risky behaviour. Results of empirical analysis showed that all groups of users got overall utility grade higher than the simulated "minimally enough aware" user, but less than "average awareness" grade. As users of all groups are highly critical towards collocutor, it can mean that users are quite aware about the importance of information security foundation, but also about lack of knowledge regarding different security issues. Another possible reason may be the users' negligence toward security guidelines and protocols.