The increasing international concern about the consequences of warfare for civilian populations has led to a growing body of demographic and health research. This research has been essential in providing estimates of war-induced excess mortality, a primary indicator by which to assess the intensity of wars and the adequacy of humanitarian responses. Far less attention has been paid to war-induced changes in fertility and population health, and the limited existing literature has rarely adopted a longitudinal approach. This is especially evident in the case of the 2003–2011 war in Iraq. Several studies have sought to quantify excess mortality, whereas other demographic and health effects of this war have been largely overlooked. This thesis fills substantive knowledge gaps using longitudinal data from the 2000, 2006 and 2011 Iraq Multiple Indicator Cluster Surveys (I-MICS). The data collected during wartime are found to be of similarly good quality as those collected during peacetime. The analysis shows that, besides causing a heavy death toll, the Iraq war also had profound long-term consequences for women and newborns. It provides the first evidence on the effect of the war on early marriage and adolescent fertility, with implications for women’s empowerment and reproductive health. It is also the first to quantify the effect of the war on neonatal polio immunisation coverage, with relevance for the recent polio outbreak. It finally assesses the main challenges to Iraq’s health sector rehabilitation efforts, namely the ongoing insecurity and persistently high rate of population growth. Overall, the findings have important documentation functions for the international community and serve as inputs for the design of humanitarian relief strategies in Iraq and similar war-torn countries, such as neighbouring Syria.