The aim of this paper is to show, with comprehensive analysis and qualitative research, why the prevention of lone-wolf terrorist attacks is demanding. This paper uses statistics on the activities of lone wolves in the European Union, analysis of the action of the police and intelligence community on counter-terrorism, and case studies of two lone-wolf attacks in Europe in 2016 in Nice and Berlin. Also, the intention is to find some space for progress in civil service activities to make the prevention of lone-wolf terrorist activities more successful. The phenomenon of lone-wolves was especially chosen because of their increasing occurrence and activity, as well as the impression that very often after an attack, information is disclosed to the public as to how certain state structures have failed in their missions. The research methods used in this paper are the deductive method, method of analysis, case studies, method of proof, descriptions, and comparative and statistical method. In the prevention of lone-wolf attacks, and also terrorist attacks in general, cooperation and sharing information between different services and their good coordination is crucial, as well as the involvement of experts from different subjects. The issue of prevention is multidisciplinary and requires cooperation between the states, a large number of security and intelligence services, various experts, the media, but also the citizens themselves which is impossible without appropriate coordination and a clear division of responsibilities.