The geographical distance between conspecific host populations is no doubt a key determinant of the likelihood that
exchanges of parasite species occur between these populations. This variable must therefore be taken into account in
studies that compare parasite species richness or similarity among host populations. This paper presents a multivariate
approach, based on the permutation of matrices, that allows all pairwise geographical distances between host populations
to be included as independent variables. The method is illustrated with 3 separate data sets on parasite communities of
conspecific fish from different lakes. In 2 of 3 cases, geographical distances among lakes had a significant influence on the
similarity of their parasite communities. The effect of geographical distance on species richness of parasite communities
also proved important in 2 of the 3 case studies. These examples demonstrate the pervasive influence of distances among
host populations on their parasite communities, and the need to properly control for them in statistical analyses.