In Tanzania, feedback of MCE results contributed in part to the implementation of IMCI in the comparison districts, beginning in January 2002, by which date mortality-data collection was nearing completion. Moreover, MCE findings helped to facilitate the timely change of first-line antimalarials from chloroquine to SP in the four study districts. Also, MCE results on equity and treated mosquito nets for malaria control have contributed substantially to the evolving national strategy for going to scale with this intervention. Preliminary overall findings from all aspects of the study – including the effects of IMCI on quality of care, household-level behaviour, child health and nutrition and child survival, together with costs – are now available. A summary statement draws these aspects together. Overall, IMCI implementation at health facility level was associated with improved quality of care, no increase in costs, and a possible reduction in mortality, suggesting that IMCI is good value for money. These improvements were observed in the presence of strengthened district health management skills, decentralized planning and budget control, and tools for resource allocation and priority setting. Improvements in health systems support for IMCI, including supervision and referral, are still needed. The lack of a community component may have limited the potential impact of IMCI on mortality and on observed behaviour change. Given the implementation realities in Tanzania, the design of the evaluation does not allow the assessment of the separate effects of the three components of IMCI. IMCI implementation in Tanzania should continue to be supported with special attention to reaching a high coverage with the community component.