Higher than expected mortality from leukaemia has been observed in the population under age 25 living around Sellafield and Dounreay, nuclear reprocessing plants in the United Kingdom. We report the results of a similar study for the population residing around nuclear sites in France. The number of leukaemia deaths was 58, comparable to the 62 in control areas, and slightly less than the 67 expected from national mortality statistics. Twelve deaths due to Hodgkin's disease were observed around nuclear sites; this is about twice the number of Hodgkin's deaths observed in control areas and twice the number expected from national mortality statistics. This observation must, however, be interpreted in light of the fact that several causes of deaths were studied, increasing the play of chance.