This paper uses a restricted sample of children under five years of age (0-4) of the 2009-2010 and 2015-2016 Tanzania Demographic and Health Survey (TDHS) data to determine the socio-economic factors of diarrhoea morbidity among the sampled children. Using a t-test mean comparison and a logit model to estimate and analyze factors influencing the probability of occurrence of diarrhea, the paper finds that there is a significant difference in socioeconomic determinants between urban dwellers and rural dwellers as well as between male headed and female headed households. Child’s age and parents’ education level were found to be negatively associated with diarrhea morbidity. Contrary to expectations, age at first birth was found to be significant only in one dataset. It is further revealed that in preventing and reducing the incidence of diarrhoea among children, sanitation facilities is of importance than the supply of drinking water. The results imply that building the capacity and providing basic health and hygiene education to parents is more important for reducing diarrhoea morbidity among children. Specifically, promotion of both breastfeeding, and of personal hygiene, while preparing the supplementary foods for these children, seems to be the right way to control diarrhoea.