1. Introduction -- 2. Measuring infant and child mortality -- 3. The development of the 2006 estimates of infant and under-five mortality -- 4. Analysis and interpretation of the 2006 mortality estimates -- 5. Is the MDG4 achievable? -- 6. Next steps -- Annex 1. Estimated under-five mortality rates (U5MR) from 1960 to 2006, by country -- Annex 2. Estimated infant mortality rates (IMR) from 1960 to 2006, by country -- Annex 3. Average annual rate of reduction in under-five mortality and progress towards the MDG target, by country.