In May 1998 a border dispute between Ethiopia and Eritrea resulted in a war lasting until June 2000, which came with significant economic cost and affected individual livelihoods in both countries. However, the specific effects on human capital of young children in the affected region still remain unclear, partly because of limited availability of suitable data. This paper investigates the effects on child human capital outcomes using the Young Lives data set for Ethiopia. Identification of the effects of the war is based on a difference-in-difference approach, by tracking the development of cohorts of children born just before and after the war, in war affected and non-affected regions. The results show that exposure to the war between the age of four to six is associated with an average reduction in height-for-age of at least 0.31 standard deviation, and an increased incidence of child stunting of 20 percentage points. These effects are persistent over time and still observed by the age of 15. This is a disconcerting finding, especially for children from poor backgrounds, as early life outcomes can have lasting impacts during adulthood.