BACKGROUND: Between 1999 and 2007, the Ministry of Health and Population in Egypt scaled up the Integrated Management of Childhood Illness (IMCI) strategy in 84% of public health facilities. OBJECTIVES: This retrospective analysis, using routinely available data from vital registration, aimed to assess the impact of IMCI implementation between 2000 and 2006 on child mortality. It also presents a systematic and comprehensive approach to scaling-up IMCI interventions and information on quality of child health services, using programme data from supervision and surveys. METHODS: We compared annual levels of under-five mortality in districts before and after they had started implementing IMCI. Mortality data were obtained from the National Bureau for Statistics for 254 districts for the years 2000-2006, 41 districts of which were excluded. For assessment of programme activities, we used information from the central IMCI data base, annual progress reports, follow-up after training visits and four studies on quality of child care in public health facilities. RESULTS: Across 213 districts retained in the analysis, the estimated average annual rate of decline in under-five mortality was 3.3% before compared with 6.3% after IMCI implementation (p=0.0001). In 127 districts which started implementing IMCI between 2002 and 2005, the average annual rate of decline of under-five mortality was 2.6% (95% CI 1.1% to 4.1%) before compared with 7.3% (95% CI 5.8% to 8.7%) after IMCI implementation (p<0.0001). IMCI implementation also led to marked improvements in the quality of child health services. INTERPRETATION: IMCI implementation was associated with a doubling in the annual rate of under-five mortality reduction (3.3% vs 6.3%). This mortality impact is plausible, since substantial improvements occurred in quality of care provided to sick children in health facilities implementing IMCI.