The Ethiopian population is very young, with nearly half (43%) of the populationrnunder the age of 15 years. This indicates that there is high potential for futurernrapid growth of the economy by using this population. Women and childrenrnconstitute 72% of the population. Like in many developing countries, childrenrnunder 15 years of age constitute a very large proportion of its population, (43%),rnof which around 40% are under five and 8% are under 1 years of age. In 2000,rnthe under five-mortality rate (U5MR) was estimated at 166 per 1000 live birthsrn(148.6 for urban areas and 192.5 for rural areas), while infant mortality rate wasrnestimated at 97 per 1000 live births respectively. Diarrhea is a major cause ofrndeath in infancy and childhood, and it is more common in rural areas where 25%rnof under five children are susceptible than urban areas where it is only 17%.rnCurrently, the coverage of safe drinking water and latrines remains very low atrnabout or less than 30% and 13% respectively. In rural areas only 4% of children'srnstool disposed in toilet whereas in urban areas 45% of the children's stool isrndisposed in the toilet. And 68% of the children's stool in rural areas is disposedrnoutside the dwelling, or thrown in the yard. These low levels of access to safernwater and access to excreta disposal are indicators of water and sanitationrnproblems which are believed to be among the major causes of the child 's deathrnin the post neonatal and childhood periods. However, the total fertility rate is 5.9rnper woman (3.3 for urban and 6.4 for rural) (DHS Ethiopia, 2000), and thisrnimplies that there are distinct differences by residence, with rural women havingrntwice as many children as urban women. Thus, the relatively high child mortality,rnwhich is in line with the theory of the effect of infant and child mortality on fertilityrnmay have led to increased fertility where mothers give birth to many childrenrnsuspecting that the probability of losing some of them is high.rnVIIrnThe National Health Indicators for the year 200314 indicate that access to safernwater and access to execrate disposal are estimated at 37.5 and 28.9 percentrnrespectively taking a sample of 10 cities in the country (Ministry of Health,rn2004). Therefore, the communicable diseases attributable to poor sanitation, andrnwhich principally affect the underprivileged sections of the population, are stillrndeemed as the major health problems in Ethiopia.rnIn line with this, this project investigated the effect of household environmentalrncharacteristics, that is, water and sanitation on the probability of child mortality.rnThe analysis is conducted using a Cox Proportional Hazards model. It is arnmultivariate model of the child's life duration, which analyses the effects ofrnhousehold's environmental characteristics such as water a nd sanitation 0 n thernlikelihood of the child's death.rnMoreover, the study found that improved water supply results in both infant andrnchild mortality reduction. However, the availability 0 f sanitation facilities per s erncould not result in mortality reductions unless due attention is given for promotingrnawareness of the rural society on hygiene practices.