A comparison was made of the distribution of the bio-and serotypes of Campylobacter jejuni and Campylobacter coli isolated from human patients (205 isolates), intestinal contents of pigs (163 isolates) and intestinal contents and livers of chickens (147 isolates). All strains were isolated in the region of Rotterdam. Campylobacter jejuni biotype 1 accounted for 86%, 1% and 82% of the human, pig and chicken isolates respectively; C. coli was present in 7%, 98% and 14% respectively. Serotyping was possible for 84% of the human isolates, 77% of the pig and 82% of the chicken isolates. Among the human isolates 33 bio-and serotypes were found, of which 22 were similar to those in chickens and only five to those in pigs. Bio-and serotypes from human beings and chickens, ranked in order of decreasing frequency, showed a positive correlation, whereas those from human beings and pigs showed a negative correlation.