Campylobacteriosis belongs to the most frequent bacterial gastrointestinal infections worldwide. In the past several years, an increasing trend in the prevalence of campylobacteriosis has been observed in many countries. The rapid spread of antibiotic resistance in Campylobacter spp. also poses a major challenge. The authors review current knowledge on the microbiology of Campylobacter spp., complex pathogenetic as well as pathophysiological mechanisms in the development and course of campylobacteriosis and related complications such as Guillain-Barré syndrome.