Campylobacter jejuni is now recognized as an import- ant enteric pathogen in animals and humans. C. jejuni was recognized as a cause of diarrhoea in dogs, since the out-break of C. jejuni enteritis in humans has been associated with diarrhoeic puppies (Blaser et al., 1979). Stray dogs and cats are widely distributed in Egypt probably due to its geographical location which is surrounded by open desert. The contamination of human food with the secretions and excretions of dogs harbouring pathogenic agents might also contribute to human infection (Siam et al., 1977). Thus this work is initiated to increase our knowledge on the role of dogs and cats harboring with C. jejuni an a focus of infection in infantile diarrhoea in Egypt.