Background: Family planning services are usually evaluated in terms of their impact onrnfertility. Less attention has been given to the way in which changes in family planning relatedrnbehavior may affect childhood mortality. Identifying the optimal interval between births atrnwhich risk of child mortality is the lowest may benefit developing countries to prioritize familyrnplanning services and achieve MDG 4. rnObjective: To Asses the child mortality rate and determine whether birth spacing is associatedrnwith increased risk of childhood mortality at a rural district. rnMethods: A house to house census carried out in 13 kebeles with an approximate population ofrn80 thousand to identify all child deaths one year preceding to the survey and to determine thernchild mortality rate at kalu district. Sex and age group matched case control study was carriedrnout after the census to assess the association between birth spacing & child mortality. Arnconditional logistic regression was performed to point out the independent effect birth spacingrnhas on children under 5 years mortality. rnResult: The neonatal, post neonatal, infant, child and under five mortality rates were found tornbe 37, 30, 67, 33 and 99/1000 live births respectively. Age group stratified analysis showed arnsignificant decline in the trend of neonatal (Xrnfor trend = 4.62, P = 0.03) and infant (Xrn2 rn2 rnfor trend = 13.23, P = 0.0003), post neonatal (Xrnfor trend = 17.06, P = 0.0001) mortality as the intervalrnbetween births increases from less than 15 months to 48 or more months. Multivariate analysisrnshowed that the odds of under five years mortality was 6.45 (95% CI = 1.53, 27.15), 3.20 (95%rnCI = 1.07, 9.57), 3.21 (95% CI = 1.18, 8.77) and 2.61 (95% CI = 0.97, 7.01) when the intervalrnbetween births is less than 15, 15-23, 24-35 and 36-47 months respectively compared to birthrnintervals 48 or more months. rnConclusion: Risk of childhood mortality was significantly associated with birth spacing. rnRecommendation: Mothers at the study district should space births for at least 36 months inrnorder to reduce the risk of childhood mortality.