Aims: The adhesion to an inert surface (the first step of biofilm formation) of the two main pathogenic ampylobacter species, Campylobacter jejuni and Campylobacter coli, isolated from diverse origins, was compared. Methods and Results: Adhesion assays were conducted in 96-well, polystyrene microtiter plates using the BioFilm Ring Test method. This new technique, based on magnetic bead entrapment, was shown to be suitable for analysing the adhesion of Campylobacter sp. strains by comparing the adhesion of four C. jejuni strains as revealed by the BioFilm Ring Test and immunodetection. Among the 46 strains tested, C. jejuni and C. coli displayed different adhesion capabilities ranging from no adhesion to strong adhesion. However, no strain of C. coli was strongly adherent, and statistically, C. coli adhered less to an inert surface than C. jejuni. In addition, strains isolated from animals or carcasses were less adherent than those isolated from food-processing and clinical cases. Conclusions: These observations suggest that the food environment and the human body could have selected strains with greater adhesion. Significance and Impact of the Study: The adhesion capability of strains could partly explain the cross-contamination or re-contamination of food products by Campylobacter. This property could provide a mode of survival for Campylobacter in the food chain.