The possible adverse health effects associated with the residence in the neighbourhood of toxic dump sites have been the object of many epidemiological studies in the last two decades;some of these reported increases of various health outcomes. The present study reports the cluster analysis of mortality and malformations at municipality level, standardized by socioeconomic deprivation index, in an area of the Campania Region characterized by a widespread illegal practice of dumping toxic and urban waste. Clusters have been observed with significant excess of mortality by lung, liver, gastric, kidney and bladder cancers and of prevalence of total malformations and malformations of limb, cardiovascular and urogenital system. The clusters are concentrated in a sub-area where most of the illegal practice of dumping toxic waste has taken place