Sixty infants were subjected to this work 25 of then having diarrhoea with teething another 25 infants affected with diarrhea without teething. The remaining 10 infants were apparently healthy, served as controls. This study was done with the aim of search possible correlation between the members of the triangle: Teeth eruption; cell-mediated immunity changes and diarrhoea. clinical and Bacteriological examinations showed no significant differences in diarrhoea between these groups. On the other hand, it was found that teething is a natural physiologic process and the occurrence of diarrhoea could be due to coincidental systemic manifestations. The immunological status of these infants is variable according to the presence of systemic disturbances. or not.