Following the 1986 Chernobyl accident, 116,000 people were permanently evacuated from the 4,200 km Chernobyl exclusion zone. There is continuing scientific and public debate surrounding the fate of wildlife that remained in the abandoned area. Several previous studies of the Chernobyl exclusion zone indicated major radiation effects and pronounced reductions in wildlife populations at dose rates well below those thought to cause significant impacts. In contrast, our long-term empirical data showed no evidence of a negative influence of radiation on mammal abundance.