For our analysis, we use the case of Jordan, a lower middle-income country that has come a long way in reducing child mortality, as evidenced by the drop in under-five mortality from over 80 per 1,000 live births in the 1970s to 26 per 1,000 in 2007.5 While this is a remarkable achievement, particularly at Jordans per capita income level, recent progress was slower than in many other middle-income countries. At this point, a fresh assessment of the main determinants is warranted to inform the policies needed to get the country back on track towards achieving MDG 4. The sample includes over 40,000 children born between January 1971 and September 2007. Differentiating between personal and biological factors, behavioural factors, and household and community factors, we find that behavioural factors such as birth spacing, smoking and breastfeeding seem to matter most for infant and under-five mortality in Jordan.6 This is in contrast to earlier studies on Jordan that had found a strong impact of household and community factors, most notably the area of residence— urban versus rural—and the mothers education level (Adlahka and Suchindran, 1985, ESCWA, 1991, Shakhatreh, Abbas and Issa, 1996).