Promotion of oral rehydration therapy (ORT) for the treatment of diarrheal diseases and the WHO case management strategy for acute respiratory infections (ARI) have contributed to significant reductions in infant mortality, but these two conditions remain the leading causes of infant deaths in most developing countries. Identification of the factors contributing to these deaths may contribute to reduce infant mortality from preventable causes. To gain insight into the circumstances and maternal and health services factors that may contribute to infant deaths we used a verbal autopsy method to interview mothers of all infants who died during the previous 12 months (June 1995-May 1996) in 11 municipalities in the State of Ceara, Northeast Brazil. Our results revealed that one-third of the deaths occurred in a hospital and two-thirds at home. Almost all the infants who died at home, however, had been examined one or more times by a doctor, and 36% of them had been hospitalized during the disease episode that resulted in death. For most (85%) of these children the causes of death were diarrhea or acute respiratory infection, and it is likely that death could have been averted if appropriate treatment had been initiated promptly. Three major groups of factors that alone or in combination appeared to contribute to most deaths were delays in seeking medical care on behalf of the parents, medical interventions reported as ineffective by mothers and delays in providing medical care to children who arrived at the hospital too late in the day to be scheduled for consultation. Our findings suggest that government efforts to further reduce infant mortality in Ceara should focus on health education interventions that address quality of home care, recognition of signs of severity and danger and importance of seeking timely medical care: and on improving the quality of care provided at community health centers and hospitals. Measures likely to improve infants' chance of survival include: ensuring prompt access to medical consultation for young children brought to health centers or hospitals with potentially life-threatening symptoms related to infections, health education to mothers on the need for continued home care after discharge and to return to the medical care facility if the child does not recover, and that they have access to medicine prescribed by hospital physicians. Further benefits could be obtained by using community health workers, now integrated into the Family Medicine Program (PSF) health teams, to provide health education, supervise home care, refer mothers to health centers and facilitate their access to hospitals.