In order to provide suggestions for conservation and management of the wolf Canis lupus Linnaeus, 1758 in Italy, a total of 46 wolves from central Italy and 53 mongrel dogs were surveyed for electrophoretic variation within and among populations. Six out of 41 presumptive gene loci exhibited polymorphism in the wolf (P = proportion of polymorphic loci = 0.146, 99 per cent criterion), whilst only 3 loci were variable in the dog (P = 0.073). Expected average heterozygosity in the Italian wolf (mean H E = 0.037) was comparable to values reported previously for protein variation in natural wolf populations. By contrast, the dog showed a comparatively low heterozygosity (mean H E = 0.020), which may be a consequence of domestication. Nei's (1978) absolute genetic distance between wolf and dog (D = 0.012) was very similar to values reported in previous investigations, thus confirming that they are closely related forms. Relative genetic differentiation (Wright's FST = 0.167) between wolf and dog was considerably higher than the mean genetic diversity found among several dog breeds. The lesults of the present genetic investigation on the wolf population from central Italy suggested that its genetic resources are quite intact. The extent of differences in allelic frequencies at loci polymorphic both in wolf and dog did not suggest substantial wolf-dog interbreeding, which has been thought to be one of the major threats to the genetic integrity of the Italian wolf population.