Invasive diseases caused by Corynebacterium diphtheria occur very rarely and when they involve Corynebacterium diphtheria nontoxigenic strains, they can cause atypical course of the disease. In the last years several articles from Poland, Germany, Czech Republic, and France have reported invasive diseases caused by Corynebacterium diphtheria nontoxigenic strains suggesting a spread of these pathogens in Western Europe.