Introduction Campylobacter jejuni a foodborne pathogen, is a leading cause of bacterial diarrhoea worldwide (1). It causes mostly inflammatory diarrhoea in individuals in developed countries, but watery diarrhoea in individuals in developing countries (2). A cholera toxin-like toxin (CTLT) produced by C. jejuni was thought to mediate watery diarrhoea (3). However, CTLT production by C. jejuni is controversial. While some investigators reported it, others did not (3). A cholera toxin gene (ctx) homologue has not been found in C. jejuni (3). There are also reports of CTLT production by non-C. jejuni species, especially C. coli, C. lari and C. hyointestinalis (4,5). We recently reexamined the question of CTLT production by C. jejuni and other species and identified the antigen that cross-reacts with CT antibody (6-8). This article summaries many findings on this line of research.