Objective: The objective was to identify spatial distribution patterns for preventable infant mortality and the main causes of death in three municipalities of Paraná state, Brazil. Design and Sample: Ecological study on infant mortality among residents of the municipalities of Maringá, Sarandi and Pai?andu, between 2004 and 2008. Measures: Data were obtained from reports by the Infant Mortality Prevention Committee, georeferenced in 19 Demographic Expansion Areas and analyzed statistically using Local Moran’s Index. Results: Of the 284 deaths among children under one year of age, 68.7% were considered preventable, and higher percentages were found in outlying areas. The main causes were illnesses originated during the perinatal period (73.8%), external causes (11.3%) and diseases of the respiratory system (5.1%). Conclusion: It is necessary to implement actions and policies on child and prenatal assistance, in order to reduce the inequality observed between the central and outlying areas of the region under study.